Every school has a different focus: rural health, Indigenous health, tropical health, research, or something else. It’s really worth your while knowing about what the medical school cares about and writing your application to suit. While you might still get an interview it’s probably not the best idea to spend your whole application talking about your interest in research if the medical school you’re applying to is focused on tropical health.
When I was applying to medical schools I wrote a really lengthy application to UNSW only to find out I was confusing it with JCU and was talking about completely the wrong thing! Just like your UCAT study, pace yourself with your applications. Think about spacing them out and spending a day on each. That said, for applications that are asking similar questions (like what teamwork experience do you have?), don’t be afraid to copy, paste, and then edit!
Before you start applying like mad you need to know what you’re applying to. This may sound obvious, but not all medical student positions are the same! You need to find out what a bonded place is, what a commonwealth supported place is, and what conditional vs guaranteed entry from a medical science degree is. Even the "guaranteed entry medicine" is not really a guarantee: there are conditions such as need to maintain high GPA, can't defer a year, have to pass an interview etc. Lots of medical schools offer different types of places and it’s a really good idea to know what the commitments for those are before you apply, or you might find yourself quite surprised a couple of years down the track.
Again, it seems obvious but it’s so important. Typos don’t reflect well on your application. MedEntry offers a really fantastic application review service (available at https://www.medentry.edu.au/our-services/interviews-admissions/application-review-service) which is so worthwhile, especially if you’re applying to somewhere like JCU where the application is super long!
Good luck and happy application writing!