I just made new covers for my icemaker and toaster/convection oven. I used a shower curtain (you'll see why in the pics) so its not waterproof - just keeps them cleaner. i may later make a plastic lining to keep them waterproof. You can also use plastic table covers. Hope the pictures help show you how-to.
First, lay your fabric (wrong side up) on what you want to cover.
Then pin the sides.
Trim off excess fabric from all four sides. Leave a big seam allowance.
Sew up all four sides. Then put it back on the icemaker, wrong side up, and turn up the hem.
Turn your hem, pin and sew.
VOILA!! You've made a cover.
IT WON'T BE PERFECT, you will have puckers. Who cares. People will just look at the overall effect. They won't be checking your seams. If you have any question, PM me.