BOOTCOVERS MADE SIMPLEby Sarcasm-hime
1. First find a pair of shoes or boots that have the shape of sole/heel/front that you want.
2. Now get some muslin or cheap fabric and cut two pieces the rough size of the finished boot. Leave extra for seam allowance, just in case.
3. Wearing the shoe/boot, place one piece of fabric on either side of your leg and start pinning, making seams down the front and back. Make sure the seams are straight and that the fabric hugs your leg (unless you're making an oversized boot).
Once you've got the boot shaping correctly, mark where the seams are (on both sides) with a pen, and also mark where you want the bottom of the cover to be along the sole. Make sure to make a few registration marks so you can match up the two sides accurately later. Now remove the pins.
4. Use the muslin as a pattern for your good fabric (do a mirror image for the other leg, of course). Sew along the front seam and the very bottom of the back seam, then insert a zipper for the rest of the back seam.
Alternately, if you want a zipper along the inside of the leg, you can sew up the back seam normally. In this case you'd want to modify your pattern piece for the inside of the leg; cut vertically where you want the zipper, and add seam allowance.
5. For the bottom, you can turn under the edges and glue or sew it to the shoe, for a permanent cover, or make a bottom piece for a removable cover that the boot slips into like a sock (use something non-slip for the bottom!).
To make the bottom piece, just stand on a piece of paper (or muslin) and trace around the bottom of the shoe, then cut out with seam allowance. Then sew to the bottom of your bootcover, matching up seamlines. It’s best to use something non-slippery and durable for the bottom. All-in-one covers with bottom pieces work better for shoes that don’t have separate heels, as these complicate matters. For shoes with a heel, you can either leave a hole in the cover for the heel to go through, or reproduce the shape of the heel and include that as part of the cover (a bit more complicated).
You can also hold the cover on with elastic that goes under the shoe, although this isn't as secure and you’d need to stiffen the bottom edge so it doesn’t gape open or flip up.
Depending on the stretchability of your fabric and the shape of your shoe/boot's toe, you may have to put in a couple of darts at the very toe.
Follow the first few steps of the non-stretchy instructions, but instead of using muslin, either use some scrap stretch material, or just cut out big enough pieces of your good spandex. Pin in the same way, but make sure to stretch the fabric over your leg so the finished cover won't be loose.
Sew both seams as you won't need a zipper in the back as long as your fabric has enough stretch. For the bottom, most people make a sole piece so that it works as a sock over your shoe, but you could also make it a permanent cover.
To make a chunky-looking boot, you can sandwich a layer of foam or padding between two layers of fabric (for my Mage boots I used the muslin pattern as the inside layer, then padding, then outer fabric).
It's possible to make covers without a seam down the front of the foot, but you'll need to do it in two pieces. For example my Lipumira boot covers have a separate piece for the front of the foot. The seams are hidden by the contrast appliqué which was sewn on by hand after assembling the boots. K'ehleyr is the same; there is a separate part that covers the join between foot and leg.
To cover shoes that don't extend past the ankle, you can get away with no seam in the centre front, but it helps if you have material that's slightly stretchy - or cut it on the bias (the diagonal of the fabric grain).
For glueing fabric or pleather to shoes, get some Shoe Goop or Barge at a shoe repair store. It's nasty, stinky stuff but it holds really well. To sew things to shoes (or anything else where you can't easily get at the back side), a curved needle is essential. Some quilting stores carry them, as well as upholstery stores.