Alternate between billing really high to fix really really screwed up projects and billing a bit lower but taking interesting projects that you can use to update your skillset. I've made 125kish a year contracting this way in the non-major, low cost-of-living cities. Plus these contracts typically last up to 5 years so you have better stability than contracts of 6 months. This is just one way, but its an easy way. I've been doing this since 1996 throughout the midwest and southern states.
I really never had a large network of contacts. I just used DICE and the like. My technique is just do as many interviews as possible when it's time. If I wasn't so lazy I would market myself better. I have a bunch of other rules but they are for when you are already on site. I can post those too if you want to know.
