1.Bring up the drum and bass tracks, set the balance between them and faders up to about -20 DB
2.Bring up Guitars Keys, etc all except lead vocal and watch meters so that they reach -5db to 0db, only occasionally dipping into red
3.Slowly bring up lead vocal until the lyrics are understandable, adjust EQ slightly so the vocal cuts through the guitars just slightly but sits in the mix.
4. Add Compression, EQ and Effects sparingly and watch over all volume. Keep out of the red and It should not "Distort" if your master is digital. If you are mastering to analog tape, you can and should hit it hard +5 to +10Db or even more.

Dom