Not sure about critical thinking. As far as i've heard it's a bit of a 'General Studies'.
The perfect application is not necessarily someone who is a complete nerd. I'd say;
Personal Statement : Honest, Concise, Filled with Experience, Knowledge of the Career, no faking.
Predicted Grades : AAB/AAA
UKCAT : Average score well above pass score, maybe 690-700/900
Reference : Outlining commitedness to education and high social input.
Experience : At least 2 days with a GP/in a Surgery. At least 4 months voluntary work in a hospital. Some shadowing of a junior doctor. General commited care-work is probably also helpful.
Interview : Honest, trustworthy, intelligent, socially apt, enjoyable to spend time with, articulate, quick-thinking, able to produce a rounded argument.
Final grades : As predicted.
I got 4 offers, and so know that my application was at least good. If you fancy a read of my personal statement (I don't in any way mean it's perfect, but it served me well!) to give you some idea of what i mean above...it doesn't all make perfect sense.