The obvious answer here would be to give them something you know they want. I'd suggest not aiming your gift directly at their disability. What they like to do would be a good starting point. Otherwise, a safe bet would be audio books or music on CD/iTunes, or gift cards for Audible.com subscriptions or something like that. Your safest bet over all would be a gift card to anywhere, be it a store, restaurant, or website. Let THEM choose what they want.

Inappropriate gifts would be like, a vehicle they can't drive, or a t-shirt that says "I'm visually impaired, feel bad for me." Most "inappropriate" gifts will be pretty obviously so.

The best gift I've ever gotten (I'm legally blind, Retinitis Pigmentosa) would have to be either a new phone or something related to my interests that I had really really been wanting.

It totally depends on that individuals interests. The blind or low vision thing is less of a factor than the choosing something that individual person may like. Find out what they are into. If they like tea, maybe a cool mug and some fancy tea. If they like audiobooks maybe an audible subscription or iTunes gift card. If they are into movies blu-rays with descriptive audio tracks may be a good idea. If they are into comedy, take them to see a favorite comedian perform, or see a favorite band perform. It really depends on that person. If there isn't a budget, maybe an iPad or some other tablet.

Innapropeiate gift ideas... Books, picture books!, magazines, whatever.

I myself am legally blind and I also buy gifts for those who are legally blind. I'm not really sure what exactly to tell you because I try to get things that I know will be meaningful to that person. One thing you can do right off the bat is make sure that it is accessible, think about how they will use it and how they will enjoy it.

 

Then just think about what they like. Do they have hobbies or other interests? Try to integrate those. I really like getting things that are personal to my relationship with that person. Last year I got my SO a mug with an inside joke printed on it in raised Braille which she loved.

 

If you are still blanking and just want a unique thing to give them I would look up things in Braille on Etsy. If that fails and you have a little money to spend, my father got me an Eone Bradley tactile timepiece last year and I've been wearing it every day since. I love it but I think the price has actually gone up on them in the past few months. I would expect to pay somewhere between $280 USD and $350 USD for it, but it's a really cool alternative to a talking watch that makes for a great conversation starter and is very useful as well as being more discrete than a talking watch.

What does the person like?
Everything depends on what they like. So just like there is no universal gift for a sighted person or someone to pick by just knowing their age or their gender, there aren't ideas that work universally.

Low vision just like blindness has so many varieties.
So some may still read even regular print. Generally: don't get a book as a gift.
A giftcard for a bookstore or audiobooks might be better.
And then knowing more about the person will help.
If you don't know anything about their hobbies or likes, some wine and some edibles might be a relatively safe bet.