Reply to Mainstream Mixing

Hey everybody, new to this community but have been following the website for a while now. Just have a few questions which i cant seem to answer and was wondering if the experienced DJ community could help me out.

The other evening i went to a club and watched the DJ, he was mixing mainstream music, a bit of everything and the way he did it i just cant figure out. The mixes were incredibly tight and he wasn't using sync or anything like that, the BPM's ranged as did the genres. I believe he used mainly EQ's for the transitions as the channel faders didn't move once and it was more complex than a crossfader movement.

He'd often use ending phrases of choruses to then mix in the next song and keep them balanced and then tune them out.

Im just wondering if anyone out there mixes like this and if they have any ways to practice it as i cant really get my head around it just yet.

Also another question, is slamming a derogatory form of mixing? I sometimes do slam when mixing songs which dont fit and im not sure if i should be doing it as often as i should.

Cheers for the help.