Tips on getting into Oxford, LSE, UCL or any other top univeristy

So I'm having to resit first year and change subjects so now I'm thinking of doing a degree in politics and was wondering if people had any advice in terms of the things I could do to increase my chances of getting into one of the top universities, preferably Oxford. By the way, I'm now going to be studying History, Politics and Economics at A levels.

Firstly what subject do you want to study? Politics isnt offered on its own at oxford. There is PPE and there is History and politcs which seem to go with your current subjects

On the Oxford website maths is a reccomended subject for PPE
Most students get in with a maths A level
Its not impossible although I would strongly encourage a PPE applicant to do maths
What makes PPE>History and politics for you then?

Well I was doing maths, physic and statistics this year and I really struggled with physics and didn’t do the best in maths so my teachers told me to drop them and take different subjects so I don’t think I’d be able to get an A if I did maths.

I guess the main reason for me preferring PPE is that I’m more interested in economics as a subject than history but I don’t mind doing history.