Okay, Sherrah, I can tell you that it sounds like your big problem might be succinctness. It’s not how much you say but what you have to say and how you say it. If you can replace five words with one – do it!
Other than that, make sure that your grammar and spelling are perfect and that you stay on topic. Tangents are bad.
That is my best advice. I also found a couple of websites that give you some great step-by-step advice.
Good luck to you!
