If you've ever considered entering just do it. This was my first time and I did it on a whim.
I printed out some photos I thought might be in with a chance, sat five friends down on a couch and paraded the pictures in front of them - vaguely similar to the judging process.
Friends picked the photo of Martine Croxall as one that most caught their eye and there you go!
However, since there is interest about the picture I thought I'd share a little more about its genesis.