I have 4 GCs and my daughter and I discuss what i buy each of them for christmas and birthday, usually a main present that she knows about then a maximum of 5 smaller, inexpensive presents, like toiletries, stationary etc. The same applies to my DD and SiL, they tell me a short list of what they'd like, in a price range I can afford, then they also get 5 small presents. I am not ashamed to say that I often buy from charity shops, especially gift sets and toys.
Back when my daughter was around five, she was inundated with presents from my mother, 3 sisters and two brothers and assorted aunts and uncles. What child needs a toyshop for christmas or 30 easter eggs!
I put my foot down, very forcefully, and insisted on a limit of 2 presents per person, talk to me about large presents, and buy clothes etc.
After the first year I noticed that this would apply across the family, at christmas, birthdays and easter. My daughter would get clothes 3 times a year, current fads in toys were kept to a minimum and I didn't need an estate car to get her and her toys home! Result!
As to charity shops, as a volunteer, and ex manager of a charity shop, new, good condit ion toys, clothes, shoes, books, media and bric a brac are always welcomed with a smile. Clothes, shoes, bags and soft toys not suitable for sale are collected and the shop is paid per bag. Bric-a-brac, and broken, incomplete toys are, unfortunately put in the skip.
(To be fair, this represents about 1% of all donations over the year!).