Nobody is perfect and that's okay! If we were, we'd be quilting in heaven. I use my 6 x 24, 12.5 x 12.5, 6.5 x 6.5, and JT shape cutting ruler. I have other specialty rulers and occasionally use them, but find the 4 mention are my go-tos. Starch, PRESS, then cut and sew. Starch again and PRESS. I still find it hard not to take my iron and go to town on a square, but I know if I do, it's going to become catty-wampuss! Just know that mistakes are okay and you will get better as you go one. Keep your first quilt and you will love it forever. It will be fun in 20 years to look at it and say "I can't believe I did that."