Gifts to other non-immediate family members go under the tree as soon as they are wrapped, but with a 4YO and a 1YO, that wrapping might take place just before the giving.

I work so much better under pressure anyway.
Gifts from Mommy and Daddy to the boys go under the tree when they are wrapped (which last year happened to be the same time that Santa made his delivery). Maybe this year they'll be there a few days before, if I'm lucky. Same for gifts to DH, and his to me.
Gifts that come in the mail from extended or distant family members get opened when they show up. I'm bad - I know!
NOTHING has bows or ribbon - Phoebe the feline likes to chew them (and on the artificial tree). Patch did too, but she went over the Rainbow Bridge in June. She used to sleep under the tree, and when I got the tree skirt out this year, it still had Patch fur on it. *sniff*
Before kids came along, I'd stuff DH's stocking a few days in advance. Now with kids, all that happens on Christmas Eve after the kidlets have gone to bed.
Penny