Firstly, align your mixing environment to a technical level using pink noise and a sound pressure level meter. There are various articles on how to do this .... for example.
Secondly, listen to lots of reference material at a set known mix volume level and train your ears to get used to hearing familiar material in this environment.
Then when you know what you want it to sound like, listen to the material you are working on - you will then find it much easier to pick out and seperate the sounds that you are hearing. The key to this is ear training, critical listening and understanding the layers of the sounds that you are working with. In a multi-track, change individual tracks and analyse the changes in sounds that you hear. You will then be able to experiment and determine what works and what doesn't work.
For instance, if you perceive that the bass is over-loud, then reduce the level in the mix. This could be due to a couple of factors: a) it's actually too loud, b) the monitoring environment is not calibrated correctly.
Compression of tracks and sounds may help, but this will reduce overall dynamic range and emotional impact. Don't try limiting the master tracks until you are done mixing. Effects on the Master track are really only for final limiting of the overall track so that it falls within technical constraints.