Imagine a number of possible outcomes. Do not stop thinking about this until you have written it all down. Stop worrying about whether or not it makes sense. You'll never get anything written if you critique your ideas as you go. Additionally, the bad ideas will inspire the good ones, so keep going for a predetermined period of time. You can increase the time you spend brainstorming as you gain experience; for example, you might start with five minutes, then increase that to 10 after a few trials, and so on for subsequent assignments.
Once you've finished generating ideas, review your list. It is time to assess the merits of your plans. The best should be kept, while the rest should be discarded. If you have enough central concepts, you can eliminate the minor ones. If you're short on suggestions, just round up the random ones and give them more weight. When is the right number of suggestions reached? You'll need some paragraphs for the body, an introduction, and a conclusion (middle paragraphs). Each paragraph in the body of your essay needs to have a central point that it establishes and defends. In order to write a five-paragraph essay, you'll need an introductory paragraph, a concluding paragraph, three key points (one for each of the three body paragraphs), and evidence to back up your claims.
Organize your thoughts into a coherent structure after you're done. In the end, highlight the most important points and ignore the supporting evidence. Using this list as a foundation, developing an outline should be a breeze.
Writing assignments for English 101 classes typically focus on personal experience and/or a piece of assigned reading, but if you get stuck, you can always do some research online before you start brainstorming.
The Resume in 99 at your university is there to help you at any time with problems like these.