Early evening and weekends. remember you are starting a business, but you need to have a life, also you want to look after the custs you have already make sure they are done but also don't get to far ahead with canvasing so you can keep up with new custs.
in my humble, look at where your work is now group it as best you can, then the week before you do an area canvis that area, that way you can work new jobs in for that week and no one is kept waiting.