Here is a basic How To's for the little green stools. If you happen to find some large spools like I did :-), this is how I covered and shaped them. The following is based on my foot stool base measurements so you'll have to adjust depending on what you have. The attached pdf pattern is not to any specific size but will give you proportions on how to make your cover and shape your foot stool.

Click here for pdf sample pattern.

Sample Pattern/Diagram 1

The above shows how I made each foot stool cover.
1) I measured the circumferance of the seat (Measurement A).
2) That gave me the length needed for the fabric to go around the stool.
3) I connected the 2 edges with zipper to make a "tube" that fitted tightly around the stool base.
4) Then with a little math, I figured out how to space my curves around the foot stool (Measurements B and C). My stool used 4 sections or curved seams.
5) I attached an extra length of thin fabric at the end of the "tube" and cinched it to cover the bottom. This allowed me to adjust and make it really tight and fitted.

1 and 2) Bare foot stool base

As you can see, I added an extra foam pad to make it a little more comfortable. You'll have to account for this in the height of your fabric (Measurement E).

3 and 4) Sewing the curved seams

After connecting the 2 edges with zipper, you'll end up with a "tube" that fits around your stool base. To equally divide your stool into four curved sections, with the zipper in the middle of one of these sections, refer to the pattern/diagram 1. Mark these sections and mark off your curved seam on the fold. I used the lid of a large pot as template for the curves. Use what you have on hand. I found that even a small curve was enough to male a big difference once you have four of them going around the base.

4) Finished seams

As you can see, the top few inches of your "tube" covers the foam padding (Measurement D) and I started the curve right under the foam base all the way down to the bottom. Trim excess fabric from the seams and notch down the curve where needed. Flip over to right side and top stitched down the curved seams to make them lie smooth and help define the structure of the shape even more.

Once the shaping around the sides is done, attach your top circular seat piece.

For the bottom, I left about 1/4 to 1/2" of the fabric to extend and wrap around the bottom rim. I attached enough of a much thinner fabric to cover the bottom, and created draw string cinch to close it off. Using a thin fabric (like liner fabric) will keep bulkiness to a minimum so the stool will sit flat on the ground. The draw string cinch method (as opposed to sewing another round piece) will allow you to easily control the tautness of the cover around the stool base.

Good luck!