Ok, I have to concentrate on what's important here...and that would be the cake...no, I mean, Dynamic Range, abbreviated DR or DNR.
1) "Know what you're trying to achieve before you set out (source: Gary Bromham)." Do you want your piece to sound like classical music? Do you want your piece to sound like Vanessa Mae? Do you want your piece to sound like Yngwie Malmsteen?! Do you want to create a sound of your own? What do you want? So if you "love the sound when you add a compressor to the mix", you are standing more on the "pop-rock-trance side of the world" than on the "natural-folk-jazz-New Age-classical" side (classical orchestral recordings are not processed, e.g. they are not processed by a compressor, nor an Eq...well...most of the times?...has anyone got statistics?). However, there's a rainbow of possibilities between those two sides...Shakespeare said "To compress, or not to compress, aye there's the point". Hahahahahaha! Well, he's not right...he's thinking in black and white, and an artist needs to think in colours, in variety. In summary, THINK ABOUT WHAT YOU WANT TO ACHIEVE, AND THEN USE THE AMOUNT OF COMPRESSION YOU WANT. Nothing blocks your imagination, you are the artist, you are in charge.
2) If you want to apply compression, consider various options. a) You can simplify the whole thing by using a compressor for all your piece at once (really rough method, lots of unexpected things can happen!). b) Or you can be more delicate by compressing each instrument (or each group of instruments) in a more intelligent way.
3) Become aware of THE LOUDNESS WAR. In your DAW, open a (high quality) recording of the 5th Symphony (Beethoven!). Select 1 minute, and make that minute fill the whole screen of your computer...and observe...you should see peaks and valleys...Dynamic Ranges alive! Now, again, in your DAW, open a loud rock track, or a loud pop track, or some strong music from a commercial, select 1 minute, and make that minute fill the whole screen of your computer...and observe again...compare. Probably, the 5th symphony will be like peaks and valleys and the other file will look like a BRICK, no peaks, no valleys, not much life usually!
=======> The loudness war, a video (everything explained under 2 minutes!):
http://www.youtube.com/watch?v=3Gmex_4hreQ=======> Loudness war (click to view the animation at the top of Wikipedia's page):
http://en.wikipedia.org/wiki/Loudness_warI hope you find this useful, I'm tired now and perhaps not making too much sense.
And please, DON'T MENTION THAT CAKE ANYMORE...