Measure each piece per block. Say one of the points is piece 1 and it is 3 x 4 - cut as many as you need with your rotary cutter 4x5. Stack all pieces in the right order and go to it. One thing I was told that really helped was:
When you are placing a piece of fabric over the space, I always was holding it up to the light, flipping it etc. Pre-fold all the lines, and crease with a fingernail (in front of the TV you can pound them out in an hour for a large qulit). That way when you place subsequent pieces, you can see where to place it no matter what side you are on. Best tip I was ever given.