To me, the most important thing is to square up each block every time you add four strips. In other words, each time you complete one round you should square it up to the appropriate size at that point. For example, if you have a 2 " finished center and 1" finished strips, it should square up to 4 1/2" the first round...6 1/2" the second round...8 1/2" the third round and so on until you reach the size finished block you want. That way each block will be the same size as all the others. It will sew together beautifully....As far as cutting accurately...measure twice and cut once...