I start from a differant perspective than most people. I don't sew triangles together. I cut out Half Square "Blocks" with my cut down method. IF you keep the corner of your template on the seams you will end up with a squared square and your seams will be even automatically.
Clickon the cut down method in my ignature below and check out how I make HSTs
Then I sew from tip to stern on everything. I never start anywhere but the edge.