You should keep all your evaluations and keep track of them. Are you improving over time ? Are you improving in some areas over time ? Are you better/worse in some topics than others ?
Take every comment with a grain of salt. Some students will hate you and/or your teaching style no matter how you teach either because they hate the topic, hate the class time, hate you, or hate your style of teaching/grading.
[It is hard to give someone the highest possible evaluation when you get a 'D' in the class.]
Look for patterns in the comments and accept that you cannot teach in such a way to please all possible students.
Strive for clarity and helpful pacing.
Even if you end up at a Research University or Lab you will have to either teach Lectures or Grad Seminars or give talks and the clearer and better paced they are the better for everyone involved.
