You mean mixing live in a club or recording a mix at home?
If it's mixing in a club/venue, it's fairly easy to gauge the crowd by looking at them, seeing what works and what doesn't on the dancefloor etc.
Warmup is slightly harder but at the time slightly easier as you've got a blank canvas to start with. You can have at it with some broad swathes of leftfield electronica or Anime soundtrack cuts if you're building your own momentum as opposed to keeping an existing one going, slowly building things up to entice people to dance, maybe an old classic or a more current cut to be dropped at an opportune moment to signify a 'here we go...' moment.
If you're playing more
peak time sets then you've got a dancefloor already. Or you should have if the warmup guys have done their job properly, nothing worse than having to come on after the opening guy has scared everyone off with 90mins of Now That's What I Call Generic Dungeon, for example. If you've had chance to see the crowd during the previous DJs set, you'll know what is working and what isn't, so you can take that knowledge and adapt it to your own selection. Boys love bass and girls like the occasional vocal, generally. But that's a broad generalisation, and every dancefloor is different so don't take as gospel.
A lot of it is trial and error. They liked that tune with the bassline and that tune with the vocal, so they
should like this tune with the bassline and the vocal that I only got sent today by this shit hot producer who is relatively unknown. Again, another generalisation but you get the idea. No hard rules here, it's a case of
taking what you know and adapting it to what you have...DJing is trial and error when you first get started and then experience takes over and it's a case of knowing your tunes inside and out, and being able to read the dancefloor and adapting accordingly.
If it's a case of
recording a mix at home, then you've got a different set of challenges as you don't have a dancefloor to specifically read. That being said, you have the luxury of time and practice, so it's a case of how you want to approach the mix. For me, how I find works is the somewhat cliched 'tell a story' approach. The mix starts
somewhere and finishes
somewhere else. I don't give a shit how good the tunes are, if it's 70mins of the same pace and BPM then it gets really fucking boring for me really quickly.
I had a technique I use for planning mixes I called the James Bond approach. Like a Bond film opens with a BIG FUCK OFF ACTION SEQUENCE then the credits and the film begins in earnest, builds towards a big set piece, then a slight throttle down and then ramped back up for the finale. In the case of Skyfall, for example;
- Opening - Big fuck off chase on bikes, Bond gets shot
- Build up - Bond recovers and returns to help MI6 catch Silva
- Big set piece - Silva escapes from M16, big shoot out and chase
- Build up # 2 - Bond and M prep for final showdown
- Finale - Explosions, guns, explosions, death
Applying this to a DJ mix using the same principles;
- Opening - Big moment to capture the listener. Could be a massive tune, quirky sampled opener, swirly pad thing, one of your own tracks, bootleg etc
- Build up - Continuing the same pace of big tunes would tire the listener out, so bring it right back down and start ratcheting up the tempo with your tunes
- Big set piece - Another burst of a big tune, maybe a vocal cut, some mixing trickery, vocal layerying
- Build up #2 - Taking what you've worked on in #3, gradually increase the tempo more and more until...
- Finale - All fucking hell breaks lose. Triple dropping tunes, acapellas, distorted gabber kicks, massive tunes, your own soon-to-be-signed future classics, whatever. A memorable end that makes people finish their listening experience on a high.
Basically telling a story. I admit it's cliched as fuck and it doesn't work for everything but it's an idea I've used before that works. Doesn't suit all music styles, obviously and as with everything is
a suggestion not a rule