Step 1: Pattern. Pin muslin around your leg and the shoe you plan to turn into a short boot. Make a mark on the pattern about 1/4 inch above the edge of the shoe below your ankle on each side. The pattern can be symmetrical, so you only need to keep one side, though it helps to have both sides while you're making the pattern:
Step 2: Cut 4 pieces from both outer and lining fabric, for a total of 8 pieces which will all be the same:
Step 3: Sew the 2 of the 4 pieces of outer fabric right sides together up the back/heel, repeat with the other 2 outer pieces; do the same for the lining fabric. Now you'll have 4 pieces, 2 each of outer and lining fabrics:
Because I'll need to know where the seamline is along the top of the spat later in the process, I like to make a line of stitching on the seamline. Or you could mark it with chalk, etc.
Step 4: Pin 1 each of the outer and lining pieces together right sides together all around except along the top edges and sew, leaving the top edges open:
Step 5: Grade the seam allowance and clip curves:
Step 6: Turn each piece right side out, being sure to push out the point of the toe end of each piece. Turn the top edge inside and sew closed. I do this by hand with a slip stitch. Now the spats are together but kind of shapeless and floppy:
Step 7: To make them a little more tailored, I like to top-stitch all the way around each spat, about 1/4 inch from the edge, making sure the lining fabric is slightly pushed to the underside:
Step 8: Wrap a spat around a shoe and see how far it is from the front edge of the spat to the first eyelet on the shoe. Here it's about 3/4 of an inch. This will be where the first eyelet will be on the spat:
Step 9: Measure between the eyelets on the shoe; you want the eyelets on the spats to have the same spacing. Here it's 1/2 inch:
Step 10: Mark where each eyelet will go on both sides of each spat. I'm going to put 10 eyelets on each side, spaced about 1/2 inch from the edge and 1/2 inch from the next eyelet. Total 40 eyelets! You can use small grommets if you like:
Step 11: Sew the eyelets or set the grommets:
Step 12: Measure a piece of elastic to go under your instep and come about 1/4 inch above the edge of the shoe, one for each foot:
Step13: Using the line you made on your pattern in Step 1, measure from the edge of the spat to the line. This is where you'll attach the ends of the elastic to each side of the inside of the spat, using either machine or hand stitching, whichever you prefer:
I haven't quite finished this set of spats, but I will show the final steps later as I complete them.
Finally getting back to this; it took me awhile to find the right laces. I use 45 inch laces for this short spat.