After finishing the track track and its mix you should work on mastering it. Here are some tips to follow:
1) Use a compressor to glue the mix and control its dynamic range
2) EQualize your track to cut unwanted resonances and boost energizing areas in your frequency-spectre.
3) To bring your track to the same loudness use a limiter. It will increase the loudness. Be sure to check the RMS level that corresponds to your genre.
This should give you a rough master. In case you want some more advanced technique check out the next prodcuer tip tomorrow, where I will introduce OTT and iZotope.