From my experience the past two semesters, I've deduced the three simple steps to garnering favorable teacher evaluations:
(1) Be polarizing, to the point of frustrating the majority of your students while earning the deep admiration of a select few. In other words, become the academic equivalent of Sarah Palin.
(2) Don't enforce a strict attendance policy. Base the entire course grade on the final paper. Make it abundantly clear that students can just e-mail it to you if they want.
(3) Distribute teacher evaluations the last day of class.
And, voila! The only students filling out the evaluations are the ones who've liked you enough to deal with your eccentricities all semester. You've biased the sample in your favor.
Which would be great, if teacher evaluations actually mattered for anything.