Here are some pictures to show MY process:
First I draw and cut out triangles.
I use either rotary cutter or scissors.
I then draw and xerox copy paper slips of triangles.
With plenty of seam allowance, exact accuracy is not needed. At this stage, many quilters trim off excess fabric, but I leave it as it is; the bulk will make the quilt strong, I hope!
I flip open to check.
Next, I finger press, pin the next triangle in place, and carry on sewing until the row is completed.
I try to place darker shades of green on one side and lighter on the other.