Aside from photos, of course; I’m thinking of things that one might buy. Parameters might be a) either small enough to carry home or shippable, b) cost under $250 or so (of course it can be way under that figure, or over a little bit after taxes and shipping) and c) probably goes without mentioning, but it should be something out of the ordinary that maybe you can’t get anywhere else.
These are the cities being visited: Paris, Milan, Venice, Naples, and the Amalfi coast including Salerno.
We shipped home Murano glasses from Venice; get them at the shops on Murano, not in Venice itself.
From Naples we brought home Pompeii artwork reproductions from the museum that has all the Pompeii originals.
We got a large pottery caprese salad plate in Amalfi.
I brought home paintings from street artists in Paris.
I don’t believe I brought anything home from Milan.
Berets and bidets. Just don’t mix them up when you get back home or people will call you an asshat.
Well, I can’t get these* here, so if you’d pick up $250 worth of them for me while in Paris I’d appreciate it.
*well, obviously I can get them here from Amazon, but your $250 will go so much farther in France.
My mother did one of those package tours of Europe and brought back a German beer stein (for me) and a scrapbook containing (clean) samples of TP from every place she used.
Postcards.
Some poor schmuck spent hours getting just the right shot of various famous places. Buy those instead of wasting your time trying to get the perfect shot. Take pictures of yourselves and focus (literally) on the people in the picture and not the background. You’ll free up time to actually enjoy your surroundings.
Ooh - ooh - I know! A miniature Eiffel Tower tchotchke from one of the souvenir vendors on the streets of Paris. For $250 you should be able to get one that’s at least a foot tall!
I lost my glasses while in Florence, and had to go to an optometrist that offered one-day (or one hour?) service. It was fun trying to tell the doctor what looked better with me knowing no Italian, and him not knowing English (or refusing to speak it); he had the receptionist help translate a few words. Anyway… Italian eyeglass frames are really cool. I’d vote for something wearable that you don’t normally see at home; those pointy Italian men’s shoes certainly aren’t sold here at Target.
We had a big purchase in Germany in the Black Forest - a real cuckoo clock. We hand-carried it on the plane, since we didn’t want to ship it (too heavy). The shopkeepers there were very good at explaining how to fill out the VAT refund forms for things that leave Europe, which will save you a decent amount of money.
Honestly? either food, wine or nothing. I hate souvenirs and never bother. We spend the money on doing things and eating things out there.
I always take beer coasters.
Losing scratch off lottery tickets can be found lying on the ground, sometimes they’re kinda cool.
I’ve bought a couple of cheap pieces of art work that caught my eye, from sidewalk artists in Africa, which are easy to pack. You can go home and hang an original.
Ancient coins or similar. Cheaper and more plentiful than in SF.
Well played!
I suggest refrigerator magnets. Our refrigerator with magnets from Germany, Austria, Albania, France and Russia
We also do this, with probably 50 magnets on our fridge. Our theme is the tackiest magnets we can find, leading to some really awful magnets in our kitchen.
In Pompeii you can also get penises with wings.
If you go through Genova on your way to Milan, you could drop by the occult library/bookstore and get a genuine vintage tome of the dark arts.
Naples has a pretty good noise music scene, so if you’re into that you could go to a show, and get an album. I recommend the group Aspec(t).
Most museums have excellent gift shops and sell quality merchandise. I just wish books weren’t so heavy, I have to be careful with those. Still, many museums have a full detailed guidebook but also have a smaller one with just the highlights that aren’t a bulky and heavy.
I bought a winter jacket as a ‘souvenir’ in Liverpool last year. It’s unique as the zipper is on the other side of the jacket. While I didn’t want to take sightseeing time away to shop for a jacket, at least it’s one I really like and was only £50. So, clothing can be both practical and a souvenir.
I tend to avoid the tourist souvenir stands unless I’m voting for my 4 year old nephew or for someone who has been nagging me to ‘bring them back something.’ Typically the T shirts sold in the souvenir stands aren’t great quality, they’re fine for a child that’ll outgrow it soon, but I’d save my money if buying for an adult.
Vintage postcards (could be of use later on if we ever have another postcard exchange). Decorative pins. Stickers. Elongated coins (do they have those souvenir coin-smashsing thingies in Europe?)
Buy any alcohol you want to bring home at a local place. I wanted a German (ie. domestic) bottle of Jagermeister. Never got one until the duty-free store at the airport. It was printed in English, not German. 
Something related to a hobby or interest.
I collect several things and I love finding something that fits one collection or another as I travel. That great hallmarked meat cleaver my wife spotted in England, that great piece of US colonial currency I found in that little shop in Canada. When I can link a trip to an interest I already have its almost like a “double souvenir”.
Type “B” batteries. IIRC they’re for bicycle headlamps.
I started a thread like this back in 2015. It’s kind of France-centric, but lots of really good ideas in there for any place in Europe. I was just looking at it last night, since my husband is due to go back and I needed to make another list for him.
Italy is known for its leather goods (most of which are produced in Florence), so you might want to take a look into that while you are in Milan, as it’s the fashion and design capital of Italy. Just make sure whatever you buy was actually made in-country, or at least in the EU!