My opinion: There’s no magic formula to it. Persevere and pimp yourself as much as possible… who you know is always a good thing, market yourself in any way you can. Most new drivers tend to resort to the agency route (after a million and one job applications you’ve made that have got you nowhere it does become more of an option)… bear in mind, wherever you get that break, a lot of it is about you as a person whether you will get repeat calls. You’ve got the pieces of paper, the cards etc. that say you are qualified to do the job but so have a million and one other people, it can be down to you as an individual that can make the difference between getting that one day of work, a potential full time job or consistent work from agencies if that’s you preference: right attitude and aptitude.
Just never take risks to impress someone though.