Are these pillows for decoration (only) - or are they to be 'used'?
If they are to be used, I would make them so the pillow cover is removable and can be washed. An envelope type is 'quick and easy' (See housewife pillow case for 'how to') or a zippered one. I would either make a 'little quilt' or line the pillow cover so that when it's washed, the pieces won't fray.
I think coordinating the pillows with the quilt would be nice - use some of the same prints.