It seems my sewing machine and the Gabardine fabric just don’t mesh with each other. I tried adjusting the settings on my machine, and I still end up with this problem:
The needle ends up catching onto thread in the fabric and pulling it, causing these weird scrunched lines. I also tried using my hands to make the fabric taut as it went under the needle, which helped, but didn’t solve the problem. It’s unfortunate because I made good progress too:
I probably should have tried different needles too, but I don’t have enough Gabardine fabric to keep trying. I think I’ll stick with a fabric I’m familiar with and get some Kona cotton.