I can hardly say I know everything about the DDJ 1000, I can say that it's an awesome bit of kit, and in the right hands... truly outstanding.
So it's nice to learn new tricks to better utilise it.
Tips:
1. Pad editor - change the performance pads
2. Midi mapping - using the sample sequence to create some nice new sounds on a track
3. FX Parameter - Add another FX to the fx pot (right hand side of the mixer), and change the strength of the 4 FX buttons (colour FX)
4. Jog wheel preferences - I love seeing the countdown to the next hot cue, it really really makes it easier to see the phrasing and get it right
5. Crossfader curve - Scratch DJ's you should know this, but for people new to scratching this is a must!