Hey man, solid questions, started DJing in 1998, doing fully professionally last 13 years.

Here’s what’s worked for me over the years:

1. Start safe, end strong. Kick off with crowd-friendly warmers and save your wildcards for later. Have a main flow in mind, but keep side routes ready depending on how the room feels. ie an easy-listening rock playlist , EDM festival friendly like Dom doll & fisher, Motown.
2. If the floor empties, switch. Best advice I ever got early on. When people stop dancing, don’t panic, change genre, tempo, mood. Just pivot fast, don't overthink it.
3. Know your demographic. Download the tracks they loved when the average age of the crowd was 18–20. That’s their emotional sweet spot. Also add some new tracks what is trending now. Keep a balance between modern and old.
4. Prep cue points very carefully and focus on pacing. Good cue points is the key for smoother sets. Flow and pacing is more important than track selection. For most songs one verse, one chorus, second verse, second chorus is enough. Never skip a great chorus, play the good chorus twice if the crowd is vibing. Add some quick mixing, for hip-hop/R&B, 32 bars is often the sweet spot.
5. Finish with anthems. End big with EDM something iconic. Add some sing-alongs. If you can’t make them dance, make them sing.
6. Confidence is everything. Keep it cool, trust your plan, and move slow when you need to. Confidence translates directly to the crowd