Need a new duvet cover? Hate all the colors/patterns you've seen in the store? Maybe you just don't have the money to buy a new one, as they can be pretty expensive.
Here's an easy fix.
1. Buy two flat sheets one size smaller than your mattress size. Ikea or Target should have good quality, inexpensive sheets. Thrift stores can also be a good source, but for this kind of project I like something new and crisp.
I know it sounds odd to recommend buying the sheets one size smaller than the mattress, but I've done this a few times, and I always buy smaller sheets . Flat sheets are usually quite a bit wider than your mattress so if you buy one size smaller, the cover should end up being the same size as your down comforter. You don't want the comforter to be floating around inside a giant cover. It will flip, and fold, and bunch up inside, leaving you with cold spots.
2. Lay out the sheets right sides together. Pin the long ends together. Stitch all the way along each long edge, just inside the sheet hem. This will give you nice finished seams inside.
3. On the short end with the wide hem, pin the right sides together and stitch all the way across. (Again, just inside the sheet hem.) This is the top end of your cover.
3. At short end with the narrow hem, pin the right sides together along one third of the end and sew one third of the way across. Then repeat on the other side. You should end up with an open space in the center of the end that is one third the width of the sheet. This is the bottom end of your cover.
5. Now you should have a big envelope with an small opening at one end. Trim the inside corners and turn it right side out. Taa-daah! Instant duvet cover! Shove your comforter inside the opening and take a nap!
If you like, you can add buttons along the opening. I've found that with a one-third width opening they aren't really necessary. If you decide you want buttons you can make the opening much wider.
If you are feeling particularly crafty, you can use the embroidery stitch on your machine to decorate the sheets. You could also sew on appliques, or make a design with fabric paint or silkscreen. Its best to apply the decorations before you stitch the cover together.
I suck at using the embroidery stitches on my machine, and I'm not sure that putty was the best choice of colors for the cover as it kind of blends in with the walls. Even so, I think this project came out just fine.
Here is my decoration...
...and here is the cover all filled up and ready for snuggling under.