Your taberunner looks great to me. Keep at it. I agree with the others regarding using lots of starch before cutting and being careful with pressing so you don’t distort the fabric. I am in love with the oversizing method and Deb Tucker rulers and Bloc Loc rulers. Both make for perfect HSTs and they both have YouTube videos. I have sewn for 50+ years and did not think I needed a 1/4” sewing guide but I have found it invaluble. Good luck. I love piecing and quilting and have learned so much here.