I would tell him now that you made him "a little something" and leave it at that. Give it to him on Christmas. That will give him a chance to give you a littlle something (a coupon book of chores, a massage...your favorite candy bar) That way its up to him if he wants to feel bad by giving you nothing.
Gifts don't have to cost money. Many a Christmas there was nothing left for my husband and I to exchange store bought gifts. But that doesn't mean we didn't exchange gifts.