Brainstorming - 5 minutes
Choose your favorite brainstorming technique and start scribbling as soon as you understand the question, the writing prompt or whatever materials or instruction that the teacher has provided.
Maybe you like to make lists, maybe you like to scribble words all over a sheet of paper and connect them with lines, or maybe you are one of those mythical creatures to whom essays appear before their eyes fully formed. Whatever your style, get going ASAP.
But remember that the most brilliantly brainstormed and written essay will not succeed if it does not respond to the assignment or test question. Be sure you understand what the teacher is asking before you begin thinking, so you don't waste time.
Outlining - 5 minutes
Arrange your ideas from brainstorming. Unless you have been instructed otherwise, go with that old standby, the five-paragraph essay. (Don't waste energy trying to get cute with structure.)
That means you need a thesis, three supporting paragraphs of three or four sentences each and a conclusion. You can do that.
Writing the body - 10 minutes
Write your three supporting paragraphs first. Make sure they are logical. Follow your outline. Keep these paragraphs straightforward and just be sure they make sense.
Writing the thesis and conclusion - 10 minutes
Write your thesis statement, introduction and conclusion. Spend a little extra time on the conclusion and thesis --- style counts. Make the introduction interesting and to the point. The thesis especially should reflect careful thinking and word choice.
Proofing and refining - 5 minutes
Read your essay from beginning to end, doing the best you can to read it with "fresh eyes," as though you have never seen it before. At the very least, be sure you have left no spelling or punctuation errors, sentence fragments, or sentences that just plain don't make sense.
Many students neglect this last step, but if you save a bit of extra time to proofread your work, the effort will show in a solid and error-free piece of writing.