I would put the heart in the center and anchor the corners with the 2 x blocks and the star and the diamond. Sashing will probably make a big difference in the way it all looks so try putting your sashing in. Also look at the top laying on a bed as it will be used. I was taught to layout your blocks putting the top the way it will be used eg- hang a wallhanging to place blocks ot lay the top on a bed to place blocks if it is to be a bed quilt. It really does make a difference in the way blocks look.