Read the prompt that the college provides. Each school will provide one or more essay choices that you can use. It is best to write essays targeted at the specific question instead of trying to write one general personal statement and sending it everywhere.
List the major events and decisions that have shaped your life. Have there been any events or experiences that might have impacted your academic record? Think about the times that you were placed in a leadership role or had to make difficult decisions.
Find one angle from which to approach the statement. Many students try to pack in too many experiences or skills. Use your personal statement to tell a cohesive story about one or two major events, unless the prompt specifies otherwise.
Write the first draft of your personal statement. Don't edit your writing as you go. Just get everything you want to say down on paper. Polish and edit it later.
Set aside your essay for a few days. By taking time before revising, you give yourself a better chance of catching mistakes and weak spots.
Schedule at least a few hours to reread and revise your personal statement. Print out a copy and read through it with a pen or highlighter in hand to mark weak spots.
Ask a parent or teacher to proofread your personal statement. Grammar and spelling mistakes will reflect poorly on your abilities to compete in college, even if the story is moving.