We usually buy for the following children:
My DCs' godparents' children (two have one each, primary/preschool, and one has 2 DCs, one primary, one early secondary).
My two DNs (teenage).
An old friend's daughter (she's the kind of friend who remembers EVERYONE'S birthday, much more organised than me)
And the following adults:
One godmother (old friend), one couple that are both godparents (family members, have no small children) and my DM and DF.
My DCs are very easily overwhelmed by presents, especially my DS.
And my DM buys for the DCs (and all these people do), usually quite a few bits though she is not offended at all if we keep some bits back.
Coupled with this DS' birthday is before they go back to school so another lot of presents.
I kind of feel like some of the present-buyers (especially the family with two DCs and the one with a preschool child) are just kind of remembering us at the last minute "oops better buy the godchildren some presents, erm, what on earth shall we buy?"
While I can and do keep presents back for a later occasion/another day/regift things that the DCs already have, it just seems a waste - I found some presents from DD's birthday party in May that I'd checked, they weren't things that she needed/were duplicates, so I just left them to be added to the stash of future presents for other DCs' parties, but clearly she didn't miss them!
I would kind of like to say to the givers, don't worry about my DCs this year. But I can't think of a polite way that doesn't sound like "honestly they don't like what you give them" (not true) or "we are holier than thou" or "my children are special snowflakes" (well maybe that's true but it's not a reflection on them or their parenting, just a fact of life that mine get overwhelmed more easily than some!).
For birthdays I tend to do vouchers/cash/something to bake/cinema tickets i.e. not something that hangs around getting in the way.
I'm also keen to cut down on plastic waste and waste in general - we only send Christmas cards to elderly relatives last year and made a donation for everyone else - I'd be fairly happy if nobody sent us one either - thankfully DS' writing is soo poor that even if all the other children in his class (Y2) send them he won't be!
But it was relatively easy to send a Christmas greetings email to those that do email and explain why; asking for "no gifts" seems really presumptuous that they were thinking of sending one anyway!