I share your pain! At quilt festival I took a class by Phillippa Naylor, and I'll try to give you a couple of her thoughts. The quarter inch foot is really important. You may have one and it doesn't work for you. Try putting several playing cards taped to the 1/4 inch line and see if that helps. Iron before cutting, iron during your work, pay lots of attention to intersections. When you pin--and I am not a pinner--put the first pin straight down at the intersection. Leave it that way, for a minute. Pin on either side of the intersection, making sure your seams go the way you want them. Now go back and place the straight up pin into the fabric behind the intersection. (I hope that makes sense) Flip your fabric over and check that everything is still in the right spot. Now sew.
I also found that using the triangulations paper (on CD)made my life so much easier. I have always tended to cut my fabric from selvage to selvage. That makes your strips wobble, and causes all sorts of frustration. Try laying out your strips horizontally to the selvage. I found that REALLY makes a difference. Last but not least, this is your work, you will always be most critical of your own work. If it isn't working right now, give your self a break, walk around,take a mental break. Go back when you aren't so frustrated. Phillippa Naylor was just coming out with a book about piecing which has been on the market for some time. Check your library, or guild, or Amazon. Good luck and I bet each of us have been exactly where you are. (Some of us still struggle! I have sworn off BOM because I haven't been able to use the triangulation's!) Good luck