what i want to do is start with a cut strip that is 3" so that i end up with finished squares at 2.5. when you start with a 2.5 strip, you end up with a 2" square after seam allowances. those smaller squares are harder for me to handle. that crummy half-inch makes a world of difference.
but if you read through all the instructions and see all the sub-cutting and odd-shaped pieces, i don't know how to get the right sizes including the seam allowances. the only thing i can think of is drawing up each and every piece on graph paper at the finished size, if i can even figure it out from the instructions,which isn't always easy, and then add the seam allowances to each piece.