I had an epiphany recently when I tried LCR mixing, restricting myself to 3 pan positions: hard left, center and hard right. It's done wonders for me in terms of clarity and width, especially in keeping the center uncluttered for maximum impact and separation in the kick, bass and vocal. I'm also experimenting with using WAY less reverb, and more mono reverbs (again panned LCR) instead of big washy stereo reverbs which take up space. I'm doing things like panning a part hard left and sending a little to a mono reverb panned hard right. Or a little delay on the opposite side.

Previous to this I had looked upon the stereo field as a full panorama and was spreading everything out to fill in all the "gaps." But of course soft panning is somewhat of an illusion and doesn't sound anywhere near as focused as things panned hard left, right or center.