Not sure what sort of 'DressCode' to go for, do I wear casual? (jeans etc) or do I go for smart? (trousers and shirt) Also any tips on the difficulty will be much appreciated and the waiting list if i was to pass all tests?
The aptitude tests usually take place at RAFC Cranwell as part as the OASC interview process. If this is where you are going then you are expected to wear a suit.
I have been through OASC before and you wear a suite for the majority of the time and tests. You need a P.E. kit for the leadership and leaderless exercises though.
If for some reason you are doing the aptitude tests elsewhere then I would strongly suggest smart but not necessarily a suit. My local AFCO RAF interviewer emphasized how important smart dress is throughout the interview process.
Suited an booted for every part of your application process. I was the only one that turned up for my initial presentation and psychometric testing (RN) and the recruiters took notice of it.
Also, if you don't already wear a watch, buy one and start wearing it.