I started this last year (DD would have been 3 then).
I had the stocking type garland too.
I filled it with a mixture of activities - draw a snow man, dance to Christmas music, go see Santa - and gifts - Christmas hair bobbins & clips. I picked them up in Claire's they had jingle Christmas bracelets & necklaces which she loved.
At the beginning of December I gave her a Christmas craft box which tied in with the activities - painting drawing making Christmas cards etc.
DS is 2 this year so I'll include stuff for him.
This year I'm doing the same activities again and interspersing with small gifts - bobbins, playdoh (small tubs) playmobil Christmas pieces small chocolates etc.
Stocking wise : (something they want, something they need, something to eat and something to read - I got that on MN)
Books
socks
underwear
stationary
crayons
colouring books
Small selection box
princess stuff - jewellery dress up things
Toy cars
Small playmobil selection
Hair accessories (you can never have enough )
A put together styrofoam plane - hours of fun chucking it around
HTH