Returning to watercolor: basics for washes, glazing, and preserving whites.

[Luke_W]

I've recently returned to watercolors after years of using acrylics, and I'm completely humbled by the medium's unforgiving nature, especially when trying to achieve clean, bright washes and controlled edges. My attempts at layering often turn muddy because I don't wait long enough for the paper to dry, and my wet-on-wet experiments just become blurry puddles without any definition. I'm working with decent professional-grade paints and cold-pressed paper, but my technique is clearly the issue. For experienced watercolorists, what are the fundamental watercolor techniques I should drill to gain more control? How do you properly judge the dryness of the paper for glazing, and what's your process for planning a painting to preserve whites and light values from the very beginning, since you can't just paint over mistakes like with opaque mediums?