Mark pointed out it'd be good to start a thread on this, im not an expert by any means so hope to learn a lot here too! :lol:
For me when i started my golden rule was what sounds good goes, i reckon this is a pretty good base to start on.
Main thing of course is to make sure you have some good sounds to compress! Compression can make a good instrument sound a lot better but it cant make a bad instrument sound good...
For my kicks (and bass(compression in general actually!)) i usually use waves C1, it sounds really tight and doesnt take up too much CPU. I try not to over compress, which is really important as it cannot be undone.. set a medium release time (say 100) and take the attack right to the top and bring it slowly down until the low end of the kick has a nice round thump to the sound.
Compressing the main bass line within a trance track is usually different with each track, depending on what sort of sound you are going for. For instance in a lighter trance track a typical bassline is quite constant, with quite a few notes in the pattern so i'd set quite a tight release (depending on how many notes make up the pattern) and again bring the attack down from the top but usually end up with quite a short attack, which can make the sequence a lot tighter.
In a typial hard trance/hardstyle track however its usual to only have 1 bass note per kick (the offbeat bassline) and in this case i usually use longer release and attack times, not by much but so the sound is a bit more open and big, but it can totally depend on what type of sound you have gone for.
Also the main thing is to not over compress by setting the threshold to low and the ratio too high... many of my older tracks were over processed and when put on vinyl came out really squashed and not as warm as i'd of liked.
Another technique i use regularly is grouping my kick and bassline together, by doing this you can make them gel together nicely by setting the right attack and release... i usually use light settings, and the most important thing is the release as this is the factor which makes the compression roll off the kick and into the bass. This can make for the same sort of effect as sidechaining.. (which us cubase sx 1 users cant do :cry: does anyone know if this is possible in sx 2 btw?)
These are the techniques i have used up to present day, as i say im really not an expert, and am still learnin myself so if anyone notices anywhere where i might be going wrong, or could improve upon please set me straight! :lol: Really lookin forward to readin up on this and hearin other peoples methods of working...