A couple of you readers did me a very nice turn by sending me this Atlantic photo essay of Paris as seen from above. It’s really wonderful, and I recommend it to all. Today I received a nice thank-you e-mail from a friend of a friend, just returned with his wife from their first trip to Paris. K. had written to ask for some travel advice; they had four days to spend, so I sent him the bit below. He and his wife were staying in Montmartre, a quarter I don’t know, so I couldn’t help there, but I did give some other advice. He wrote to say they’d followed my Day One and Day Two suggestions, and had a great time — especially at the Luxembourg Gardens.

If you followed my blogging from Paris last fall, none of this will be a surprise to you. But if not, this is how I would suggest spending my time if I only had a few days in Paris, and didn’t know the city:

So, Paris. Staying in Montmartre will put you off the beaten track, but the metro is good and easy to use. There’s a free app from RATP, the Paris metro system, that helps you navigate it. You put in where you are, and where you want to go, and it tells you the connections to make. Invaluable.

 I think you are absolutely correct to avoid the rush, especially in the summer months. I’d say forget the Louvre, where the lines will be insane. If you have to visit a museum, I’d suggest the Musee d’Orsay, but plan to get there very early, or the line will be awful. The line situation will probably be a lot better at the Cluny museum, which is devoted to the Middle Ages, and is a pretty awesome place.

 Forget too going to the Eiffel Tower. You’ll waste hours in line there. We didn’t learn until it was too late that you can, and you should, make reservations weeks in advance from the US. It might be worth going by to see it from the ground, though.

 We have three kids, which meant we rarely could afford to eat in restaurants. We enjoyed buying meat, cheese, bread, and fruit from neighborhood markets, and making our own lunches. I would suggest doing the same, not only because it’s more affordable, but because it’s very Parisian. Make sure to take a corkscrew with you. Nicolas is the local chain of wine stores; they’re everywhere, and will be able to help you find something good to drink in your price range.

 You must must must say “Bonjour, Madame/Monsieur” when you walk into a small shop, or greet a clerk in a supermarket or big store, and say “Au revoir, Madame/Monsieur” when you leave. Americans don’t know this, and are always taken as rude by the French when they just wander into and out of stores without observing the social code.

 I would also make sure you have a good data plan on your smartphone. Googlemaps make it impossible to get lost, and easy to find your way around.

 If it were me, I would schedule my time as follows:

 Day 1: Montmartre and environs. I spent very little time in that part of the city, so I’m not very helpful, I’m afraid. You’ve seen the film “Amelie,” I guess; it’s set in Montmartre, and offers a very romantic view of the quarter.

 Day 2: St-Germain and Luxembourg Gardens. Paris really has to be seen on foot, and there’s no better walking to be had than on the Left Bank. This is Hemingway’s Paris. Don’t know if you are a fan of his memoir “A Moveable Feast,” but if not, you should read it on the plane over. I would propose starting early at the Musee d’Orsay, then going on to the rest of the itinerary. If you decide not to do the museum, just go straightaway to the rest of this. Near the Orsay is the rue du Bac, a wonderful walking street. It dead-ends in the Pont Royal. You’ll want to start just south of there. There’s a great bakery called Eric Kayser on the rue du Bac, not far from the river. There are six Eric Kayser branches in Paris, and they’re among the best in the city. You cannot go wrong with anything you buy there; it’s well worth a stop. Down a bit more is a Parisian must see: Deyrolle. It’s a taxidermy store, but that doesn’t begin to describe the Old Curiosity Shop wonder of this place. You are thinking: “Why would I go to a taxidermy store in Paris?” Just do it, and see for yourself. It’s magical.

 After that, I’d suggest wandering down the street until it intersects with the Blvd St-Germain, then hanging a left. It’s such a great walking street. Before long you’ll come to the place where the Cafe de Flore is across a side street from Les Deux Magots, and both are across the boulevard from Brasserie Lipp. If you’re a fan of Hemingway and/or 20th century Parisian intellectual history, you’ll recognize this as Ground Zero for literary cafes. It might be worth having a coffee at the Flore just to say you did, but it’ll cost you an arm and a leg. Nearby is the old abbey church of St-Germain-des-Pres. It’s worth stopping in for a look. It was once a great and powerful church, but during the Revolution, was turned into a prison. Most of the abbey was destroyed.

 After that, cross the boulevard and head south down the rue de Rennes. If you want to do something quick and easy for lunch, duck into the big Monoprix just down the block. They have a nice cheese section there, and charcuterie, and it’s pretty affordable. You can buy bread there too, but if you were smart, you already bought some at Kayser. You can also get wine there, and it will be good; I find that I appreciate the guidance at Nicolas, though. I’d take my lunch over to the Place St. Sulpice nearby — only about a six minute walk away — or, even better, to the Luxembourg Gardens, about a 12 minute walk (make sure you walk through Place St-Sulpice on the way to the Gardens). The Gardens really are the glory of Paris. Find a nice place to sit there and rest, eat, and drink wine, and be happy together. The best cozy green spots are in the southwest quadrant. Don’t miss the old men in berets playing boules.

 Now, you have a decision to make. If y’all are big foodies, I don’t see how you could resist a trip over to La Grande Epicerie, way down the rue du Bac. It really is out of your way, though. If you go, I strongly recommend you look for the confiture made by Christine Ferber, and bring back a few jars. It’s about $9 per jar, so not cheap, but it’s insanely delicious. If you’re not into that, you can safely ignore La Grande Epicerie, however. An alternative plan could be to walk down the rue du Bac from Deyrolle — it really is a great walking street, one of the best in the city — until you get to LGE, then shop there for your lunch fixings (buy wine elsewhere; it’s high there), and stroll over to the Luxembourg Gardens. After lunch in the Gardens, exit on the north end, on the west side of the palace, and make your way through St. Sulpice over to the St-Germain-des-Pres church, and the famous cafes. After that, stroll down the boulevard towards the Place St-Michel, or even better, cut over behind the church to the rue de Buci, and get lost in the Latin Quarter.

 If you take the prior itinerary, avoiding the Grande Epicerie, exit the Gardens at the northeast quadrant, on the east side of the palace. Amble down by the Odeon, cross Blvd St-Germain, and wander the narrow streets of the Latin Quarter, taking it all in. It might be fun to end up by the river, and go for a stroll before heading back to Montmartre. If you still have time, though, you might want to walk over to Shakespeare & Co., the famous English language bookstore. There’s a much less visited, extremely cramped and musty, irresistible English language bookstore called The Abbey, which might be worth a peek. Also, just behind Shakespeare & Co. is a fantastic church, St-Severin, which is an excellent example of Late Gothic.

 After all that, you will have had a very full day. The metro at Place St-Michel is a major hub, so you can connect easily to the right one to get you home. You know, though, we got used to using the bus system, which we liked even better than the metro, because you see so much of Paris with it. We Americans have a prejudice against buses, but in Paris they’re clean and safe and great. That RATP app helps you find the right bus and bus connections. The thing to do is to buy a carnet of tickets at the ticket-vendor, which will save you the hassle of having to do so every time you want to use a bus or get on the metro; if you need to pay the bus driver, you can, but they’re grumpy about it.

 Day 3: The Latin Quarter/Ile St-Louis/Marais. Take the metro or bus down to the Place St-Michel, and pick up where you left off. If you have an interest in the Cluny museum, it’s right there, near the metro. Afterward, or instead of, It’s worth a short hike up the hill towards the Pantheon. I wouldn’t recommend the Pantheon, but part of that is my inner reactionary Christian talking (it was built as a neoclassical church, but turned into a secular temple by the Revolutionaries). The thing to see is the old-style Gothicky church next door to it. That’s where the only remains of St. Genevieve are. She was a fifth-century nun and healer who is the patron saint of Paris. During the revolution, a mob burst into the church, removed her body from its tomb, dragged it off to the Place de Greve across the river, burned it, and threw her ashes into the Seine. One of her bones had been kept as a relic in a convent outside the city; that is all that’s left of her, and it’s entombed in a side chapel at the church. I visited that church a few times, and prayed for the martyrs made by the Revolution.

 Take a left on the charming winding road down the hill. Now, if you’re a Hemingway fan, you’re still in “A Moveable Feast” territory. You’ll recognize the streets and place names from the book. At this point, though, unless you really want to go down the rue Mouffetard, I’d continue downhill towards the river, and head for Notre Dame, stopping somewhere on the Left Bank (that is, before you cross over) to buy lunch supplies. Lunch will be a lot more expensive closer to the cathedral.

 After you see the cathedral, walk eastward to the Ile St-Louis, and head down the main street there towards Berthillon, the most famous ice cream shop in Paris. They sell Berthillon ice cream at several places on the island, but it’s worth trying to get to the original shop. You can taste everything there, and it’s all spectacular. I was particularly in love with the Agenaise, which is the French version of rum raisin (it’s dried plums soaked in Armagnac). Enjoy your ice cream by the river, then wander over to the Right Bank, into the Marais, the old Jewish quarter. There’s lots of good walking and shopping there, and a wonderful place to eat: the Breizh Cafe. “Breizh” means “from Brittany” in the Breton language. There they make both sweet and savory crepes, in the Breton style. Order a bottle of dry Breton cider with your crepes; it’s a very special treat.

 After that, I’m not sure what to suggest. I guess it depends on your preferences. It’s about a mile down the rue de Rivoli to the Louvre. You’ll probably be worn out from walking by that point, so you might consider a bus or the metro. Even if you don’t go into the Louvre, it might be worth walking around the grounds, just to see the palace. Or you might want to head back down to the river and spend your last hours on your last full day just strolling by the Seine. Can’t go wrong with that.