GW Washes
I haven\'t used them in my serious projects yet, but I\'ve screwed around with them over white primered minis, and with a really light base coat, like GW\'s Ice Blue, Yellow and Shining Gold.
You\'re not supposed to add water to them at all.
You want to wash the whole surface first, letting it dry before going back over the recessed areas. That will get a good contrast, especially if you mix the Badab Black wash with whichever other color you\'re using as your second coat.
The Baal Red doesn\'t do anything to add contrast to red paint, sadly. It\'s better as a shading for yellows.
The Griffon Sepia is good over gold.
Purple looks cool over Ice Blue.
Keep in mind, I\'ve only experimented with these washes in fast and loose painting, and not in my higher quality painting yet.