Parametric EQ ? Oh so you're already used to the frequencies division !
Parametric EQ 2 is better if you have it.
Do you know that when you have many instruments, if you want them to not be all mixed in the same pot, to be easily distincts for the ear, it's possible de "allow" frequencies to each instrument (following his "preference").
Here is a screen about repartition of frequencies :
http://puu.sh/kJzi.jpgAbout the
Stereo Enhancer, you it's also a good way to choose directions for your instruments. Bass must be in the center, and with a short spectrum ; things like pad, strings etc. can really be dislpayed to the left/right with large spectrum. The important thing is to cover all the "room" of the ear. The spectrum grows with the left button of the Stereo enhancer. The middle one is the shift between left and right (or right and left). The last before volume is just de direction of the sound.
Here is a example of a large spectrum in two directions :
http://puu.sh/kJzD.jpgHere is the final when you have all your instruments good setted, if you just put each spectrum on the other :
http://puu.sh/kJzP.jpgAbout the
Compressor, that's a usefull efect that allows the sound to not be too "hatched", more regular. When many instruments are loudly playing, it "compress" the volume, when only one play the volume is a bit lourder. Put that on the instruments like FPC (battery), or when you play a lot of notes in the same time. Also on the master thing, it's interesting, to have a more "polished" sound, more pro maybe.
For now just use the Threshold to choose the amount of reduction, and the ratio to set the compression. Maybe the gain if you want so.
Finally, a song I'm currently working, a good example of spatialization I think it's intented to be "spatial" (in the sci-fi way). You'd need good bass headphone or something but I used a lot of the effect above :
http://soundcloud.com/ziassan/stellar-insightAnd another one for the stereo aspect, you'll hear in which way :
http://soundcloud.com/ziassan/cheery-algorithme