I'm working on a carpenter's block and do lots of stars.. yes, you did pick a difficult one.. a few little hints for this.. or any block with lots of converging pieces. precision is the key. I make a template.. then I lay it on the back of the fabric...mark around it. then I mark my 1/4" seam allowance.. cut it out.
do this for every piece.. pin the pieces together precisely and make sure every one is stitched right on the lines. For the center star, I stitch the points into pairs. then I stitch 2 pairs together, so I have 2 halves. then make a single seam across the halves. I stitch mine by hand so when I get to converging points, I take small "tacking" stitches to match pairs of points so there are no "belly buttons" in the center, and the points are all right there.
for the outer star ring I stitch the sets of 3 points together. then I set the squares in between the central star points. Make sure the point of the square
is aligned with the "corner" of each star point. then stitch in the diamond trios and finish off with the outer squares and triangles. Oh, and as with any block.. be careful not to stretch any bias sides.