... also...I did.
 
Thanks.

Fleer
Did two.

ewe

ewe tewe?

As Jeff says, attack is usually the most critical setting and often the best place to start. I think one of the reasons people struggle with attack settings is they don't have a practical mental image of what different lengths of time sound like.
 
For example, say you want to allow the initial crack of a snare through...just how long does that attack need to be? Is 10ms too long or too short? How about a bass drum? Or a vocal consonant? How much longer is an "S" versus a "T"? The pluck of a fingered bass versus that of a picked bass?
 
To get to the point where you just know where to start with attack (and release) times, you have to first be able to mentally correlate audio events to units of time. The quickest way to learn that is to zoom in on transients in your DAW and let the timeline tell you how long they last. You might be surprised to find that many events are much shorter in duration than you think, and that you've been unwittingly setting your attack times too high.

Jeff nailed it on compression!

Caa2: yah, that's the way to do it...don't guess at the answer, figure it out. Science! It's not just for nerds.
 
Your images reminded me of another aspect I should have mentioned: the period of low-frequency waveforms. For example, the low E string on a bass has a period of 24 milliseconds, meaning that's how long it takes to complete one full cycle. Attack times less than 1/4 of that (6 ms and less) are shorter than the rise time and are thus going to distort the waveform in a clearly audible, and usually inharmonic, manner.
 
Granted, sometimes that's a desirable side-effect. But not always. Take the spectrum into account when setting attack times, and don't forget that compression across the master bus encompasses all frequencies.

 

"Mix/Mastering compression - how to choose?"

 
well, the first thing is to make sure that you are not confusing mixing, with mastering.
 
the approach to either of those,
is completely different.
 
 
then, you have to ask yourself,
are you wanting to 'color' your mix,
or control it?
 
 
once you've answered that,
you can do the homework and discover which style, type or model of compressor is best for what you want to do.
 
then you can acquire the compressor.
 
then you can start to learn how to use it.
 
sorry if that seems oversimplified,
but it is just that.
 
 
no one else can 'learn' you about what kind of compression you are going to want on a 2-bus or while mastering,
but the reasons for using a compressor to begin with, should guide your choice.
 
 

I WAS Looking at those charts,
what the heck is that all about?!
 

Off. The charts.