This may not be the best way, but it's the way I did mine.
LONE STAR TUTE
size of finished star 42"
Step 1
Cut strips 2-1/4" wide by 42" long and sew together, insetting each color 2 inches to look like a stair (I used 9 fabrics). Press seams open.
Step 2
Cut strips 2-1/4" wide at a 45 degree angle.