Do I wait until their parents tell me not to buy for them anymore, otherwise just continue giving? I would feel awkward saying I'm going to stop, or just stopping unannounced.
Don't stop unannounced. Start the conversation at Christmas, or in the new year. Say that you think it makes sense to stop at 18 (or 21 or whatever suits you), ahead of time, and so that each child has had the same number of years of receiving presents when it stops for them.
I do feel it needs to end at some point. As a child, none of my aunties and uncles gave gifts except when we were small, certainly stopped by teens.
No, looking back, I don't remember getting presents from Aunts or Uncles - I presume it must have been agreed by my parents and my Aunts and Uncles when we were small.
Personally I would tell everyone to stop gifting for my child when they are 18 but it's more difficult suggesting it for others' children! Even now we're at the stage everyone wants cash or gift cards, it's becoming merely a transaction!
Exactly. The act of everyone passing notes round is a bit daft.
As good a reason as any to stop when they get to a certain age.
However, it isn't difficult to explain that is what you are going to do. In fact, that is the easy bit, as you can control that. I can see it might be more awkward if you are related to someone who wants to still buy for your child, but that is on them.