I love the tutorials on the Missouri Star Quilt Company site as well, Jenny and her girls make it so understandable and fun. My quilt blocks got much better when I started having a consistant 1/4" seam and pressed all my blocks using starch and setting the seam, then pressing "to the dark side".
You will get better with each block you try and each quilt you make. I am self taught and my first quilt was a disaster in quilter's terms but it was well loved for years by my daughter!