I've made log cabin blocks using 1 1/2" strips, and no matter how careful I was each block was slightly different. Since they were just for placemats, I squared up each block to the same size. Having said that, I just finished making a queen size log cabin quilt using 2" strips. After each round, I squared up each block to the same size, then did the same after each round, even if it was only just a tiny trim - the quilt turned out beautifully and I'm very happy with it - just sent it to my niece to LAQ it for our family reunion in July as she has a long-arm. The one time I got absolutely perfect blocks was when I paper pieced the log cabin blocks. Hope this helps, but 1 1/2" strips can be a little challenging - but take it one step at a time and you'll do fine.