I agree with feline fanatic. Trimming or adding to the blocks doesn't solve the inherent problem. It's time to go back to basics. Cut those 2 inch strips. Sew two of them together. Iron them to the side and see how big is your result. It has to be 3.5". If it's bigger, then sew a fatter 1/4" seam. If it's smaller, then go to a thinner thread for sewing, ie 50 or 60 weight or learn how to sew a scant 1/4" seam. It took me a while to understand that if I wanted a quilt to go together right, I had to get my result down right. So many people think it is only about that 1/4" seam and it is not. It is about the resulting size of the block.
Edited to Add: A scant 1/4" is maybe 1 thread less than the first 1/4 that you sewed. Sometimes, it's 2 threads.
It could be your cutting. Look at some YouTube videos on how to cut. I was centering the cutting line on both sides and ended up a bit small. Measure your 2 inch strips after you cut them and see what size they really are before you start sewing.
Last edited by Barb in Louisiana; 08-29-2018 at 07:30 AM.