I LOVE HANDMADE CARDS...... my girls do them every year also my eldest daughters school does a christmas card thing where the school children draw a picture and it gets printed on to xmas cards which are SO cool.
with the hand made ones i used card and would do a handprint or footprint here is some we do and have done:
reindeer: paint your LO's foot, print onto card then draw 2 antlers one above the small toe and one above the big toe (aprox.) draw on the eyes add a red glitter nose and draw on the mouth!
you can also do a robin with a handprint, the handprint being the body and wing and the you add on a little head and beak and legs.
father xmas face using an upside down handprint for the beard then add the rest!