Welcome Rachey - for your Christmas Eve box, it depends on what you want to do with it - is it to keep DC busy in the daytime (so colouring pages and baby crayons, or a toy, or a DVD to watch together would probably be best for a just turned 1 yo)? As DD gets older, you can make it more about craft kits, or ingredients to make cookies for Santa, etc.
Or is it to help the wind down to bedtime? Ours is, and has:
New pjs (for all 3 of us, DD, DH and I!)
A Lush Christmas bath bomb each for DD and I (the Ickle Bots are lovely and lavender filled, as DCs get older there are great festive ones to use too)
A posh hot choc each for all 3 of us (I get the "lump of chocolate on a wooden spoon" types, different flavours to suit us all)
DD's plastic Christmassy plate and glass - to put out Santa's cookie and milk
DD's stocking
The family edition of "Twas the Night Before Christmas" - which is never read in this house until Christmas Eve (loads of other Christmas books get read through December but this is saved) - we bought that for DD's 1st Christmas and it's still tradition to read it now (she's 12 on Boxing Day this year!).
So it's a mix of old things that come out every year, and a couple of new things to be used.