Omni Covers The Easy Way

by Arrakis

Materials and Tools Needed

an appropriate length of cloth. Cotton and Polycotton broadcloth and quilting cotton are generally good choices.
a way to sew (machine, overlocker, handsewing supplies
measuring tools (yardstick, quilting ruler, ruled cutting mat, etc.)
cutting tools

Measure around your omni with a tailor's measuring tape or with a string that you then measure with a ruler. Cut a rectangle of fabric about 4" longer than the area you want to cover and 1/2" wider than your omni is around. (This assumes 1/4" seam allowance; adjust to your preferred seam allowance). Sew it up the long side to create an open tube. Test fit and resew if needed to tighten the cover as desired.
Sew straight across the tip from the seam to close it.
Pinch the fabric to separate the two sides of the cover.
You can fold the tip so that it looks like this by changing where the cover is folded. Rather than folding along the seam and the half-way point, the seam is now on the flat part and the fold is 1/4 of the way around the tube on either side.
Open the tip up like this.
Now, draw a line. A bit of curve makes it nicer. It should cut off about this much of the triangular tip.
Sew on that line and trim. I'm using an overlocker here, but it is the same procedure with a regular sewing machine or handsewing.
Do that for the other "dog ear".
Turn it right side out and put it on! If the remaining corners are too bothersome, get back in there and take a couple more stitches until you're satisfied. You'll get the feel for it quickly.