Cut your pieces. In total, you’ll cut two of the front piece (Piece 1) and two of the back piece (Piece 2). If you’re making these reversible and you’re using two different fabrics, cut 1 of the front and 1 in the back of each.
Now match front with front and back with back, right sides together. Pin along the leg holes and the top seam. Sew these down! When sewing the back piece, leave a 1” hole where the tag would usually go- this will be our hole that will allow us to make these seamless and reversible. The only other areas you will leave open will be the sides.
After sewing, attach elastic onto the same exact seams we just sewed, again making sure not to sew the 1” hole in the back.
Now take the FRONT piece to the right side. Insert it inside of the back piece, which is still inside out. Inserting it inside should make it right sides together. Have the front piece lay flat inside of the back piece, then pin the gussets and each of the sides together of the front AND back pieces.Sew the gusset and each side!
If you’re doing this correctly, you should be sewing across four layers of fabric
Now simply take the suit to the right side using the hole we left in the top of the back piece. Finish off this hole with an invisible stitch, then you’re all done!
That’s it! If you don’t have an hourglass shape, I’d suggest adding an inch or a few inches to the waist, as it’s definitely shaped very narrowly.