[noiseflaw]

If you are new to mixing and you want to increase the overall level of your mixes, it is worth considering a few options:

Compression.
One way to increase the volume of your mixes is to compress and sometimes very heavily, the instruments in your mix. What this can do is to even out the overall volume and help reduce the peaks that can trigger clipping. Compression also affects the tone and character of your instruments.

Putting a compressor on the 2 Bus can also smooth the peaks, thereby increasing headroom.

EQ
Paying careful attention to the frequency content of your mixes is extremely important for many reasons, but regarding volume you will need to isolate those frequencies in your mix that may also be causing clipping - do you have a build-up of energy at a particular frequency range that is causing you problems when trying to raise the volume.

Mix Levels
Is your mix well balanced?, is the snare too loud or is there too much low frequency content causing reduced headroom?


Limiting
This is where a lot of volume and damage can be achieved! It is not uncommon for some music to be limited at levels on or around -6gb gain reduction. Of course there are negative artifacts with this...

Try seeing how far you limit your mix without noticable effects.

Just a few things to consider - others will chime in, I hope they are of some help.


p.s. You have to remember that the skills and expertise of the engineers creating those mixes and masters and the equipment they use is incredibly high - it is not just a piece of cake to match that quality.