Producing with a variation of BPM and key can help bring out the best of a musical idea. 

Despite this issues may arise when it comes to DJ’ing as in most cases the track will be played at a different speed than originally produced.

As a general rule of thumb I find that if you produce a track in a low key, choose a BPM at the lower end of the scale. If the track is in a high key choose a BPM at the higher end of the scale. This way if a DJ speeds up a slow track it tightens up the low end, and if a fast track is pitched down it still sounds big.

If you produce in a high key at a slow BPM you risk it sounding thin when pitched up. Also by the other end of the scale if you produce a track in a low key and it’s slowed down the low end may end up sounding too deep and flat.