I very much feel you. Choosing customers is crucial. Patio11 has some great write ups on the type of customer who will suck your life force: Retail, not much

I very much feel you. Choosing customers is crucial. Patio11 has some great write ups on the type of customer who will suck your life force: Retail, not much money, not very busy. Rather have business clients who are less price sensitive and have better things to do than argue about font choices. I had one lady who spent 75 emails sending me on wild goose chases for a $30 app. At one point she mentioned a refund and I processed it before she could change her mind. She then offered me a job. Noooooo.