Basically what you're looking to do is to decrease the dynamic range of the track. Generally most people will take individual tracks like the main melodic instruments, the kick and snare, and the bass and saturate/compress/limit them. There are tons of tutorials out there on how to compress instruments properly so I won't go into it very much but generally do most of the work with the compressors, lowering the dynamic range, and then use the limiter lightly (probably never passing 6dB gain reduction). If you want more bite on your kick and snare, try using a soft clipper and clip them a few dB after compressing, as a substitute for limiting. When you finish your mix, export it in a raw format at 24 bit and then master the outputted track. There's also a ton of tutorials on mastering so I won't elaborate very much but try using an eq for last minute leveling, a little saturation, some multi-band compression and "glue compression" (google it; Waves SSL Comp is pretty good) and limiting/clipping. That will hopefully allow you to gain a few more dB. Hope this helps.
