when i started 3 yrs ago i bought £22k worth of work and did a bit of canvassing when my van was in a garage for a week, and although it was a bit daunting i got into it after a few doors, just try and keep positive and aim for high priced work.
thankfully i havent had to canvass since, but if i had to i would do it. make sure your on google maps, gumtree, and yell advertising, doesnt cost a bean.