I don't know about you - but when it comes to my comforter or duvet cover - I'm really picky. And it doesn't help that all the duvet covers I love are super expensive. So back in our college days I decided to just DIY it and make my own duvet cover. It was so easy and cheap that I don't know if I'll ever go out and buy one.
Want to make your own using my minimal instructions? Well this is what I did. I bought 6 yards of fabric for the part of the duvet that you see (the top) and just used a queen size sheet for the back. You could get away with buying less fabric - but I like having leftovers (for pillows, etc). Next I cut three 22 in x 74 in (I think) panels (obviously do your own measurements). I sewed the panels together to form the front and then placed it on the comforter and pinned the sheet to the front piece (right sides together with the comforter in the middle) to make sure it fit right. Then took the comforter out and sewed up 3 of the sides.
The side I left open was the bottom of the duvet. I purposely made the top piece longer so it would overlap the bottom side. I sewed button holes all along the bottom of the top panel (button holes are actually super easy) and then sewed buttons to the bottom panel, aka the sheet.
What the back of mine looks like:
Insert comforter, hand sew the comforter to the bottom panel (just an X in each corner) so it would slip and slide everywhere and you are done!
Here is the original comforter that I've had since I was a teenager.
My first duvet cover (don't you love our cheap college set up?) ;)
I machine stitched the stem and sewed on the flowers by hand.