Changing the seat covers is an easy way to revamp dining chairs. A coat of paint sometimes helps, too. :) For my new (old) dining chairs, I kept the look simple with basic black-on-black.
I found the chairs (and matching dining table) on craigslist. The chairs were sturdy, but the seat covers were in horrible shape.
The original covers had been gold, like the chair on the left above. The seats were later covered with a beige fabric (by someone who should never be allowed near a stapler again).
After pulling out what felt like 10,000 staples, I removed the beige fabric to reveal... more staples!
When I tried to remove the ancient gold fabric, it practically disintegrated. After pulling it off the first seat in strips and strings, I decided to leave it on the other seats. To help smooth out the worn corners and provide a bit of padding, I added a layer of white fleece.
For the main cover fabric, I used some black velvet that I had on hand. I laid it out, placed the seat on top, and cut the fabric about 2-3 inches larger than the seat.
Keeping the fabric taut, I stapled it in place, paying special attention to folding the corners.
I spray painted the chairs black and put the seats in place. Done!