I don't see anything wrong with your wall hanging. I would be excited if my blocks turned out like this. Have you seen how to do the half square and quarter square triangles from squares? Seam diagonally 1/4 " each side of the center then cut down the center. Or sew around the square and cut diagonally both ways across the block. I have seen some tutorials on this board for these tricks. Then Saturday I was watching Fons and Porter and one of the tips they said was when you are sewing the blocks (like on the four patch) have the bottom seam pointing toward you and the top seam top seam pointed away from you. It matches the seams up beautifully. Hope this helps.