I would say 6 weeks is the optimal amount of time to revise for the UCAT, but this does, of course, vary per student. You should start of by familiarising yourself with the different sections and all of the different question types. Work out what you're naturally good at and what you struggle at. A big mistake I made last year was immediately trying to do a lot of timed questions. Instead, I would advise using youtube tutorials and medify tutorials to briefly build up your technique so you can tackle questions more efficiently. For QR, get used to using the on-screen calculator. For AR, make a list of patterns that you don't get right the first time, and briefly look over the list at least once every two days. For VR, learn which questions to skip and how to skim read long paragraphs. I would seriously advise against doing more than one mock a day - if one goes badly it can be very tempting to do another, which is what leads to burn out. Overall, take it slow and steady, get used to the time pressure and hugely focus on your weaknesses. Also do not neglect SJT - a lot of people from my school got scores of 2900+ but a Band 3 or 4 at SJT, which completely sabotaged their application. Good luck!