I would show you my method (which is not mine of course). I am still learning you know
Its Rhonda's and you can find it here with full details
I am fixing two stripes of fabric, sewing them at one long side
After ironing to one side
I use 2.5 " square template to make a half square triangles in an Easy way
By the way Templates also from Rhonda check here
you can see HST's ready to use
I can make more by turning and sewing the other two sides .