Well, when I first started reading about the basics behind mixing, I was able to come up with a system that works for me. Basically I'm a person who relates everything in life to math. I think of mixing as trying to place an object in 3D, except in this case we have sound instead of objects. In the physical word objects clip each other and can't be inside each other and by translating this convenient truth over to mixing... sounds shouldn't be placed inside sounds.
On my X axis, I plot out my stereo panning.
On my Y axis, I plot out my frequencies of the sound.
On my Z axis, I finally graph my stereo image.
To manipulate the data on each of these axes we have several tools:
X axis - Uhm... your panning knob?
Y axis - This goes straight back to where your sound is created and can be manipulated right up to the point where a track is about to be mastered. Using detuners, unison, Equalizers, you can manipulate the sonic soundspace the sound resides in, therefore moving it up and down on our virtual graph.
Z axis - Well, you have a few tools for your stereo image. The most common being reverberation, and delays. You also have tools such as stereo enhancers etc.
NOTE: When playing with stereo image I recommend you don't use headphones, as they don't actual produce sound in stereo but rather binorially. (Use monitors or speakers if you lack the cash).
Now, while you may have tools to modify the values of your xyz, you still don't have tools to measure them... oh shit! you do!
Measuring your xyz:
X axis You have something called a db meter. use it.
Y axis Nothing beats Voxengo Span
Z axis Stereo imaging is still a fairly new concept to me, and I therefore don't know the best monitoring suite for this, but one of my friends recommended I use IXL, which is an entire metering suite, but they have a stereo analyzer as well.
Anywhosal... That's the way I think of mixing. Yarp.
