The writer has to make pleasure for the reader - which, I think, is done by taking one's character's seriously and taking one's readers seriously -don't condescend or try to be tricky. Be a friend to your reader - I'd say that's a pretty good first step.
As far as the work I did with Timbaland, it was his sound and I just kinda floated in his direction. I just rapped over his traditional beats.