AccuQuilt GO! Is a great way to make sure your cuts are right on the money, but if you don't have that luxury just be extra cautious with your rotary cutter. You can do this.
Now, in this example I have two half square triangles which need to finish at 3" + .25" seam allowance on each side. So once they are sewn together, the square unit should be 3.5".
Next I want to share a board that I use often. It is just a piece of foam board from the school supply section with a piece of spare batting glued to it. I have these in many sizes and at least two per size. It's like a mini design wall.
Once the center is sewn, it is time to measure again. Since this finish size is 12", I know that the outside rows should be 3" each and the center should be 6" + .5" total seam allowance (.25" each side).
If you have any questions or if you are interested in purchasing your own AccuQuilt cutter to help you start strong, please let me know.