Yeah I honesly only tried doing two types of advertising, and those were the worst in the world (AT&T advertising solultions tried it two years before, and Service Magic). I never tried doing door hangers or EDDM, it might be something to consider. I did get stuck in that situation like most bid to just get the job, in fact I was underbidding myself. Alot of those customers where cheap or late payer's, not the greatest customers at all and I should have just came clean with them and say "hey this isn't going to work out, I'm ending our service agreement effective xx/xx/xxxx", or gave them the quality of what they were paying for. But getting rid of those few to focus on the great customers that offer or have the potential to offer more, and that refered me to their friends and family.
Note I won't be leaving my full time job, granted the pay is okay, but the benifets are what really keep me there. Plus there is a enough time around when I'm scheduled for to run this part time for now.