The fabric selection is entirely up to you. Some folks do color ways, others have done holiday prints, all from the same fabric line or just novelty prints. It is absolutely up to you. My rule of thumb is to not buy any new fabric and to make sure the little candies are something that I would like to receive. But again, that is your choice. Have fun with the swap and know that you can be a random as you wish as long as there are no duplicates.
Yes, baby news please, NZ.