Making straps is one of my least favorite things to sew. It is hard to sew a narrow band, then attempt to flip the whole thing inside out. I will avoid projects that have straps I hate it so much, well that is until I learned this nifty trick.
You will need a long length of cloth and a piece of string. Embroidery thread is best.
Place the thread dead center of your piece of fabric
Pin your thread in place at the end of your fabric. Pin along the sides making sure your thread stays as far away from the edge as possible.
Sew the edge, and the end of the string in place. I will go over this 2-3 times to hold it in place. There will be a lot of tension on this end.
Sew up the long edge, leaving the short end open. Keep your thread from the edge at all times, you don't want to sew it into the long edge.
Make as big and obnoxious of a knot as you can at the edge you stitched the thread in place.
Now the tricky part. Flipping it inside out. Slowly start pulling on the thread sticking out of the open edge. helping the cloth fold over onto itself This is wear the embroidery floss really helps, I have had threads just break on me, but the floss works every time. Keep pulling and flipping it over, and you are there!
I like using a zig zag stitch down the center to help hold everything in place.
And you are done! You have a fantastic strap for your purse, tote, or whatever project you are working on.