Here is a duvet cover I made for my spare room a while ago. I was in love with lemons, limes and oranges. I embroidered all of them by hand and drew the designs out for each.
Instead of buying a pattern you may or may not like buy a transfer pencil for a few dollars, draw out your own designs or trace them from coloring book pages, photographs, anything where you like the image (more simple lines are usually easier)I used regular printer paper and had no problems. Trace over the image with the pencil (**Note-if you are doing anything like letters you will have to trace on the back of the paper so the letters show up the right direction-hold the paper up to a window and trace.) Place the image with the traced picture down on your fabric and iron with a medium hot non steam iron. I always hold the image in place and gently peak under a corner to make sure it transfers before lifting the whole thing up. Once you are done sewing everything wash your item and the transfer "ink" vanishes. I love these pencils because they let you be endlessly creative for very little money.
I bought a plain white queen size duvet for this project but you can use 2 queen size flat sheets and sew around them on 3 sides and put buttons, snaps or a zipper on the fourth side. Stuff your duvet inside and you are set.
I used the back side to make a cherry duvet (Post to come). Two for the price of one!