After stitching the pieces of your project together, iron the seam open.
Step 2: Sew bias tape
Cut 2 strips of bias tape that are at least as long as your seam and about 3/4 of an inch wide. You can either use pre-made bias tape or make your own.
Insert one edge of the seam into a folded strip of bias tape and pin. Stitch along the fold line, back stitching and the start and end.
Step 3: Repeat on other side
Repeat this for the other edge of the seam, and it’s done!