How should you structure your personal statement when applying for Medicine?

It is important that your personal statement is personal to you, so while advice is useful it should not be taken as law. Be sure to incorporate your own style when writing your personal statement so that is it a true reflection of yourself.
Having said that, following a basic framework may be useful in the early stages to help you get off the ground. There are some important things that need to be included in a personal statement, especially when applying for Medicine.
Intro: This show be short and succinct, briefly outlining what course you want to study (in this case, medicine) and highlighting any personal reasons as to why. Feel free to be as artistic as you wish but avoid using cliche phrases such as "I've always been fascinated..." or "ever since I was young...". Maybe try avoiding quotes as well, they can seem tacky if not done well.
Body 1: The body is where you should talk about your work experience and voluntary work that relates to the course. For Medicine applications, this is the most important section and needs to be detailed. It is important to not only say what you've done, but also highlight what you've gained from the experience and how it informed your decision of applying to study Medicine. Students who may have had a lot of experience often fall into the trap of wanting to list all the places they've been to, but neglect to reflect on what they actually gained from the experience. So, as a guide line, I suggest talking about two clinical placements (e.g. hospitals, GP clinics) and one voluntary placement (Nursing Home, St. Johns Ambulance etc.) Say what you did, pick out a particular moment and describe it in detail, and explain what you gained from the experience and how it informed your decision to study Medicine. To help structure your writing even further, you may decide to have a paragraph for each placement. Some worry that this part may take up too much space in your personal statement, but describing your work experience in this depth is impressive and shows a level of reflection, a skill necessary when pursuing a career in Medicine. It is possible to be detailed without waffling!
Body 2: This is where you talk about everything else about you - your sport, your hobbies, your achievements in school etc. This should not be a list though. Instead, try to relate everything back to your suitability for the course. For example, instead of saying "I captained my football team..." try saying "The leadership skills I have gained from captaincy of my football team further highlight...". Note that for Oxbridge applications there is less emphasis on extracurricular activities but more on "supercurricular" activities (things that directly relate to the subject you want to study, such as subject books you've read, subject workshops you've attended etc.). So if you're applying to Oxbridge you may want to consider refraining from talking about extracurricular activities in detail and focus more on expanding discussion about your work experience, or highlighting your supercurricular activities.
Conclusion: Your conclusion should ideally briefly summarise your ambition to study the course. You do not need to repeat anything you've said early, but instead offer a conclusion as to why you feel this course is the best fit for you/ why you wish to pursue this course. Some people may want to discuss their future ambitions in the conclusion. This is fine but just be careful to keep it short and sweet!
Other tips: It is often useful to not worry about character limit especially in your first drafts. Write freely! Characters can always be cut down when approaching your final draft. As mentioned before, avoid using cliche phrases and words, but also try to vary your sentence openings and structure. Instead of starting every sentence with "I" consider other options. One good technique is to take the verb of the sentence and use it to start the sentence. A thesaurus is your friend! So be sure to use one if you're struggling with cliche words. Just be careful to not use language you wouldn't normally use (it still has to sound like you)!
Remember that a personal statement is a reflection of you, so try to express your enthusiasm in the way you write! While the personal statement is an important part of the application process, it is forms part of a collection of information Universities use to inform themselves about you, so don't stress!