This is what i did, pick area's well as i found that nearly all newer estates were better covered than a lot of others. This is not to say i have not picked some up cos i have but generally had a better response from older semi housing area's, i used to leaflet every monday afternoon and usuall gained at least five by the end of the week and so on and so on. Leaflets seem to give you a foot in the door in a street and once you are in doing a good job the word spreads, its slow but does work. I could have gained twice as much work if i wanted but now have just short of 250 customers in my first year and stopped advertising for windows around 3 months ago.
if you are not bothered knocking on doors do that, i personally distaste people selling anything at the door, but if you have no problem with this, go for it, its a good life most of the time but you need to set goals for yourself and take the knocks and p*** takes that you will definately get
good luck simb0