I am a big fan of the ‘hat’ costume: a hat so fantastic that you can just wear normal clothes and it still counts as a costume.

Gnome Hat
Supplies:
Worsted weight yarn in Red (I used Red Heart Super Saver in Cherry Red - 1 skein should make 2 hats)
Size G crochet hook
Yarn needle
Scissors

Gnome Beard
Supplies:
Small amount of worsted weight yarn (I used Red Heart Super Saver in White)
Size G crochet hook
Yarn needle
Scissors