I'm thinking of ways to be up-front about the fact that my friendliness doesn't mean I'm a push-over.
Too many times, recently, have people assumed that (because I'm generally easy-going), that it also means I'm willing to be ripped off, or gullible, or something. As a result, I turn into their worst nightmare.
I'm thinking that the next client that compliments me on my behavior will get a response like, "Just don't mistake that for someone isn't willing to employ a 'scortched earth' policy.", and possibly an explanation of how I do not enjoy teaching people a lesson in what I'm capable of.