These shorts - oh these shorts. I really recommend using stretchy sequin material, or buying two pairs of sequin shorts in red and blue, cutting them in half, and sewing them together. I used this material:
These are sequins sewn to a slightly stretchy mesh material. Since this is a bit see-through, it needed a backing fabric, and I used satin. So that meant a lot of messing around trying to create a good pattern. I used a combination of a Burdastyle shorts pattern, and another pattern made by copying an existing pair of shorts (made by covering shorts in masking tape to create a template)
This kind of sequin fabric is a bit annoying because it sheds sequins everywhere. There are still sequins in my bed and on the floor. You need to pick sequins out of the seam allowance so that the material can go through a sewing machine, though these sequins were so small that both my overlock machine and sewing machine could sew over them. Try to save any fallen sequins - you might need them.
The next step was to baste the sequin pieces to the satin pieces, then sew them into shorts. I also added bias tape to the leg hole so that the sequins wouldn't scratch me. Here's my cat, Pearl, helping me. I had to sew this by hand so that the stitches wouldn't be visible from the outside, and because I didn't want to try passing all the through the sewing machine.
So much work - and only one side is done!
Hours later and the blue side is almost done
And now sewn together
I made my pattern too big by mistake, but this turned out to the advantageous, as it allowed me to add an elastic waistband, which was a lot less work than a zip.