Start now. It’s just a page, but it can take a very long time to write and perfect and often the most difficult hurdle is getting some key ideas down on paper. Start by just making a list of the main things you want to include in your statement that you think are essential. Then start crafting paragraphs for each of those key points, such as independent reading, an interesting recent internships, etc.
When you mention anything, make sure to explain why this matters. What has being team lead for the school badminton team meant? Have you developed leadership skills? Learned how to better build team harmony or deal with internal conflicts? Always explain how a particular activity has made you a better potential university student. Bear in mind also that while it’s fine to mention extracurricular hobbies, especially in a Medicine personal statement, this is the aspect that tutors will be least interested in, so don’t talk too much about it.
Don’t lie. Even inadvertently. You would be amazed at how many students mention books in their personal statement that they never actually got round to reading, or even worse, read but then forgot all about! Make sure you can talk at length about anything you mention in your personal statement – nothing will make you look worse in an interview than if you draw a blank when they mention something from your personal statement!
Don’t try and innovate. Including jokes, writing in an unusual style or including sarcasm are nearly always a very bad idea in a personal statement. Your key goals should be to keep the personal statement to the point and clearly written; every line should reflect how you have strived to develop yourself academically.
Review Review Review. Do not submit the personal statement without at least 3-4 different sets of eyes having reviewed your personal statement. Parents and teachers are always good starting points, but also consider any family friends, especially those who have professional experience of reviewing resumes, as a personal statement is quite similar to this.