My preference is for mostly avoiding cities when on tour. Camping arrangements can be very different depending on both preferences and locale. In some areas like Oregon and California there are lots of nice state parks often with cheap hiker biker sites. On BLM land and much National Forest land you can do dispersed camping. In many small towns in places like Kansas, Oklahoma, and similar areas camping in small town park's picnic areas is usually fine (and free). I try to avoid private campgrounds, especially the ones that cater mostly to RVs, but once in a while use them as well.