How should I prepare for an Oxbridge sciences application during Summer?

Oxbridge applications are holistic - adequate time should be given to all parts of the application (mainly the personal statement, pre-interview assessment (PIA) and interview). This being said, in the case of a sciences application, the majority of time should be spent preparing for the PIA and the interview. This is especially true for an application to Oxford, as approximately only the top third of those who sit the PIA are invited to interview (vs approximately 80% with Cambridge).I would recommend completing the personal statement early on in the summer, before focussing time into the PIA, whilst starting some interview preparation. A strong performance in the PIA will lead to an invitation to interview, and will leave about a month to prepare more fully for the interview.