if you are going to touch the platter then its best to avoid tunes that have the following at that given moment:

String sounds
Ride Cymbals
Strong Synth Lines
Any sound with an elongated release time.

try l;earning to touch the record between beats in a rhythmic fashion, this will reduce drag time and minimise any audible effects.

The pitch fader technnique is far superior than touchincg the platter and gives results which are hard to hear and have less chance of going wrong. The possibility that you might be bumped or touch the platter too hard cant be overstated, and in a lcub environment its not gonna sound good, although club systems are often much more forgiving than bedroom setups.