Having done quite a few of these things from psych interviews, ink blots and WOMBAT tests to multi-choice questions (all of which I somehow passed), I think the best guarantee of success is to do your research, tell them what they want to hear, don't mention the bad bits (we all have them) and be consistent.
These days operators are looking for someone who 'fits in' is not a one man band, has good CRM skills and follows rules and procedures.
I still think that the best way of selecting pilots is to put them in an unfamiliar aircraft or simulator with someone they have never flown with before, give him/her a problem and watch what happens.