Couple tips away from the DJing side.

If you got longer tracks, import them into a music production software and make your own DJ edits, export them back and use them.
Also check out Mastermix DJ Edits. Tracks have been slimmed down to around 1.5-2.5 mins and have 8 bar intro/outro on them.

Set a couple hot cues and loops over chorus/instrumentals and you can mashup your sets getting a lot more creative.