A good friend of mine got married yesterday, and I was the officiant at his wedding (I'm legit). I wanted the ceremony to be meaningful and thoughtful. I wanted to do a good job. So I started by figuring out what I would say to the couple if I were only given the chance to express one thought at the ceremony. That took some time to figure out, but once I had it, the most important part was done. The beginning, middle and end just served to introduce, support and sell that one all-important message.
When you're writing a paper, giving a speech, filling out a college application, having an interview, or meeting with someone important and you're trying to figure out what to say, start by asking yourself, "What's my most important message?" Start there and spend some time on it. Your most important message deserves the most time and attention.
Boil everything you're thinking down to the one thing, the most important message you need to get across, and the rest will fall into place from there.