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Mixing buckets (or old paint cans): for mixing glazes
Painting Techniques
Painting Large Murals on Walls/Floors 
Henry V, 2007 (set design by K. Cameron)
Using Projectors
1. Make a slide/image file of the outline of the image you want to put onto the wall. You only need the basic outline, as you're trying to get everything in proportion - you can fill in the details later.
2. Project said image onto wall.
3. With chalk, marker or light paint, copy the image onto said wall
4. Turn off projector, fill in details of image
Using a grid system
This is more useful for large images that need to be painted on a floor.
1. Get a copy of the image you want, and superimpose a grid over it. 4 x 4 usually works alright, but you can up the number of squares depending on the size of the area the image is to be painted on.
2. Copy this same grid onto the floor using chalk line.
3. Copy the rough outline of the shape onto the floor with chalk, using the grid as a guide. Sticking chalk on the end of a pole so you can draw standing up works well to keep you at enough distance to see whether the overall shape is correct or not. 
Grid mapping in theater class. Not an actual set, sadly.
Stippling
Stippling can be done in many ways. In all cases:
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