In my family we have always given one present per person to those who we would be with at Christmas - no sending of presents to others. My Dh was brought up with the rule that all children were given presents, but this stopped when they were 18 and grown up.
I don't like that rule much, as it is difficult to teach children to give presents if they are not expected to give the grown ups something, however small.
We have always tried to find something the recipient really wanted, but have tried to limit expenditure. Between adults we agree on an amount of money that is not to be exceeded for presents, but obviously, you can choose to give something cheaper if you want.
I think it is very important not to give children too much at any time. If the child is the only grandchild/ niece / nephew with lots of adults wanting to give, we tried to get them to give one big present from them all, rather than lots of things.