Jenny R,
Remember the RAF want you to be an officer first and pilot second so you have to convince them this is what interests you (although in reality it's the other way around).
I would recommend having some idea what would be invloved should you be offered the job/sponsorship. Things like how long you will be at IOT.
Also know how old you are in years and completed months - that one caught me out a few years ago.
Good luck...