- Be wary of entering into agreements if you are already busy; or, alternatively, desperate. Too busy, and you may renege on your end of the bargain. Too desperate for work, and you can be taken advantage of. - Find a personal contact within a large company that you're working for. Make sure they can rely on you for honest communication and prompt fulfillment of your promises. Then, you can rely on them for flexibility, good projects, and dealings with Accounting (read: getting paid).
- Figure out how best you negotiate rates as a contractor. If the other party is being difficult, you have two options to protect yourself: either be firm for the initial talks and give discounts as you see fit, or compromise at first and be firm on that compromise.
Huh. I know more than I think I know. Talk and practice are different animals, though. It's tough work working for yourself!