There are several schools of thought on whether they like pilots trained or 'blank canvases' and anyone who gives you a definitive answer doesn't know what they are talking about.
What is guaranteed to help you is
* RDF (formerly FCA) membership
as you get extra marks in your interview for having these
What is likely to help you is
*Proven Leadership and Organisational skills
*Proven interest in aircraft and the military
The selection process (well, the first stages anyway) consist of them anwering you routine questions about yourself and grading your answer. Simple as. Very impersonal. Then they add them up and give you a score. Top scores get through to the next stage.
Knowing someone (NOT CANVASSING!!) who is familiar with the format of the officer interview will help you enourmously, as they will tell you how best to sell yourself.
Gaisce, mountain rescue, Lifeguards, scouts RDF etc etc are all useful to be involved in, and being a captain of a sports team is a real plus as well. You should use this time to build up a deadly CV for the next time they are hiring. You need to be able to give them examples. They'll say stuff like "Tell me about a time when you showed organisational skills / leadership" etc etc and you got to answer.
I was going to give it a lash to see how I got on but I fear that by the time the hiring comes round again it will be too late.
Smoke me a kipper, I'll be back for breakfast.