[bashville]

I'd say set your final stereo plug to a very mild setting (a little rise on the high's, a little compression on the bottom), then leave it alone, and work on your mix with that plug always active. That way you're always adjusting within the boundaries of the character of that plug, if you're sure you'll be leaving it in.

Regarding the soft-loud question: search the web for information on the Fletcher-Munsen curve. That will help illuminate some of what Naagzh was talking about. Also, sometimes when you mix too loud you tend to think things are in balance when they're not, because with everything loud you can usually pick out the part you're focusing on. Listening softer, each element needs to occupy a narrower dynamic range to be heard properly in balance throughout the full length of the song. That means each thing not being too soft when it's at its softest, and not being too loud when it's at its loudest. It takes experience to find out what you like to do on each kind of part, because it won't be the same for everything.

You can almost mix softer as you go along. When you start you may find yourself bringing things up slightly to hear details of individual parts, but the more you get the blend, it helps to bring the volume down to hear that all the parts are making themselves heard. Strangely enough, fans and other ambient noise sources have a similar effect by raising the noise floor, instead of turning your mix down.