origami...
Origami invitations are pretty popular... now you can continue on that theme

beaded...
Beaded using your colors

a wooden aspen leaf ornament...
it can be any ornament, of course, but it's a nice keepsake

My favorite would be to go to a clay center and make some super cool ceramic rings and glaze them... that would be a GREAT favor!

whether it's beads, feather, flowers, a family tartan or engraved pewter... it's a great way to personalize the table and your guests would have a great keepsake...