I look at it two ways:
1) If people are coming to hear the DJ, plan your set…
2) If you putting it out there for them to listen to, Don’t plan, feel the crowd.
You always have your bangers in your DJ set, what you end up resulting to is a set that you’ve either played or wanted to play.
I personally plan my sets…1 hour at a time, with a 5, 10 and 15 minute set. works for me…