i find the best way is to knock as you put your flyers out, this way you are on hand to give a quote on the spot if asked, having done that this will boost your ego no-end and really get you going, as for those who are not in a least they are aware of your services, 1 tip is to look out for is really filthy windows especially if there are several houses like this in a row (always a good sign that there is no w/c in that road) on a good day you may achieve 5-6 houses per hour of knocking providing you pick the right area
good luck!
jay