To get the level of loudness that you are used to it takes a mix where everything is nailed down and tight with a carefully balanced low end.
Something like Voxengo SPAN is a good tool for looking at your RMS power in real time. The lower the number the louder a mix is. A thin mix can be pushed to around -10db RMS power and a fatter mix usually does about -12, which is slightly quieter. Some really thin mixes are as loud as -7.5 or so, some examples of uhhh low tuned metal that are mastered to 7.5 or so are After The Burial's Rareform and Meshuggah's Obzen. I recommend mastering at around -12. Loudness is a necessary evil, but anything louder than -12 and you're really making a sacrifice to participate in the loudness war. At -12 I feel like I'm not losing anything or compromising.
The amount of low end affects how loud audio can be mastered without pumping or killing punch and attack.
A good mastering chain that doesn't get too complicated is a compressor followed by a limiter and then some metering.
With compression, if you can hear it working easily you have applied too much. You want a 2:1 ratio and just set the threshold way up so that it barely kicks in. Never any more than 2-4db of compression should happen.
With a limiter, use an intelligent look ahead with as few settings to look at as possible. Listen to how the attack and punch of the drums change.
Preserve the punch and also make sure that the way it does change is positive. The mix should be subtly glued together by the compressor and nothing else. It should be sensed more than heard working(no pumping). The limiter should make the guitars sound all crazy and exciting with the drums, but once again it shouldn't be heard working. Kicks should never sound rounded off and cymbals should never be heard sucking in and out.
Go for those goals while watching your metering and listening to the balance of the low end and you'll be there.
Another tip is to make sure your monitoring setup reproduces all of the frequencies that are present in your mix. You can hit a wall and be like "Why is this quiet mix pumping?" and it will be because something low down that you aren't hearing well or at all is causing problems.
SPAN is free:
Real-time audio spectrum analyzer plugin (AU, VST) - Voxengo SPAN - Voxengo