I recently purchased a swimsuit and need to alter it a bit to be comfortable wearing it. I’m trying to insert a stretchy strip across the back to give more support to the bust. What I get is a gosh-awful mess on the underside–bobbin side–of where I have stitched the piece to the suit. How can I make it come out right?
Also, when making a T-shirt out of cotton knit, how can I do the hem around the bottom without it stretching all out of shape? My sewing machine does not have differential feed. I usually end up doing the hem by hand, but then it doesn’t stretch with the fabric. Any advice?