Are you sitting while you cut your fabric or are you standing up to cut. I can not get my blocks to work right if I sit while cutting them out. Which I have done on some in the past and they are always wrong. If I stand over my mat when I am cutting, and keep the cutter vertically- no slant, holding the blade so it is just touching the ruler edge, I have good success. Everyone else may not do theirs this way and what may work for one may not work for you. But there are so many ideas given here that you can try. I would recommend practicing on some very inexpensive fabric or lots of scraps, until you are comfortable with working with a rotary cutter, and you can get you blocks the way you want them.