Compression can definitely destroy your track if not used properly. True, it's easy to look at meters and see what clips/doesn't clip or jump out, but one of the most difficult things is learning how to actually HEAR the compression and what it's doing.
My teachers used to explain that it's a "breathing-like" sound that you hear your signal doing. Although I believe that's a good way to put it, you'll never fully recognize the sound for yourself until you A/B the mix with/without the compression.
Some of the obvious things that stick out (especially when overdoing it, just to be able to recognize it without subtlety) are that the loud volumes get hushed, and the whispers and breaths get loud.
What else does it do? You'll notice that although compression and equalization are two completely different things, compression DOES affect the frequencies in your signal, whether you like it or not. Take a lead vocal that happens to be very sibilant (presence in the 7-10kHz range)... Put that through a compressor and make the ratio high and the threshold low and you'll notice that it will be much less sibilant than it was. Take a vocal track that has a low presence and do the same thing, and you'll hear it thin out slightly.
Basically, it's okay to use it. Overuse is very common in amateur production. (As opposed to back in the days when amateurs couldn't afford compressors and their mixes would be too quiet). Be moderate with compression and you'll LOVE it.
But remember that a MIXED song is a MIXED song. That's what it means... Mixed. Most of you are probably tired of me spelling this out, but I can't say it enough: MAKE SURE YOU MIX YOUR TRACK BEFORE YOU PUT A COMPRESSOR ON THE MASTER.
As for the other stuff... I usually won't compress a kick drum track that is already one signal (i.e. it's one sample of a kick drum with one level or MIDI velocity). If a kick drum was banged out by an actual drummer, then I would compress it so levels wouldn't go haywire, and maybe gate it too, so that I wouldn't get leakage from the snare drum and toms. I MIGHT compress the overall drum sub-mix to tighten it up a LITTLE, but I like the fact that my kick is driving the record. Just remember that if your kick is very loud compared to the rest of your mix, if you put a compressor or limiter on your master fader, your kick drum will be the one thing that limits everything else. Try it with a very loud kick, and then mute the kick half-way through the song and you'll hear everything get dramatically loud.
As for vocals... well, I compress the living shit outta them. I usually compress when tracking/recording so my levels won't clip going to tape... then I compress individually on tracks, as each vocal is different and independent from the rest... THEN, I sometimes bus all the vocals out to a sub-group and compress that too! And if I have a compressor on the master, then that's FOUR TIMES that the vocals have gone through a compressor! Which means "Compressing in moderation" has a whole new meaning. I have to make sure every time I compress I will do it VERY moderately and JUST ENOUGH to make a slight difference.
I hope this little rant helps in practical matters of compression. Read as many articles as you can on the matter and it will help AS LONG AS YOU PRACTICE alongside your reading to make sure you GET IT and HEAR IT.
P.S. Good shit, Open Mind... You seem to be taking this seriously and reading articles as they're gold and then seeing the results when you practice what was preached. Keep it up.
-Hypno
iam gettin familar with compression and understand its use on LIMITED DYNAMIC RANGE area.its growing on me and its one of my favorite FX.i highly recommend to do lots of audio test with it besides reading articles to fully understand and hear what compression does and whatnot.