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Common misconception: A scenic painter has to be "artyartsy". Not so. Do you know what dirt looks like? Good. Can you trace someone else's drawing projected onto a wall? Awesome, you are a-ok for 90% of scenic painting tasks. That said - plan to your talent base. If you need to do lots of intricate wood grain or cornicing patterns or suchlike, you might want to find someone who can draw for at least those parts.
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Co-ordinate with your set designer and talk about what kind of effects he wantsthey want. If he they wants a super-realistic looking set, make sure that you have a plan for how you can create all the textures and colours involved. If not, see if you can go with something more clean and symbolic looking.
Also, co-ordinate with the costume designer! Not many scenic designers think about this, but it's important that a) the colours colors don't clash b) the styles of the costumes and scene don't look odd together. Very intricate costumes work best against either completely plain sets or equally detailed texturing. However, they tend to look odd against very stylized or cartoonish non-textured painting. At the same time, if your actors are all wearing blacks and your scenic painting is very detailed, the audience will wonder what the technicians are doing on stage. Make sure these things work together!
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Mixing buckets (or old paint cans): for mixing glazes
Painting Painting Techniques
Painting Large Murals on Walls/Floors
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Step 7: Finally, add stippled “features”: basically anything stippled that is meant to actually represent something more than a texture – e.g. moss, rust, lichen, dirt stains, dried blood...
These sometimes need several texture colours colors themselves, depending on the area they cover, but often simple orange (for rust) or green (for moss) stippling will do. 
Heavily stippled wall from Twelfth Night, 2008 (set design D. Habib)
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Good for detail work and beloved of the perfectionist and masochistic scenic painter. Put a little bit of paint on the end of the brush, hold it exactly perpendicular to the surface, and pretend you’re Georges Seraut (i.e. make lots of little dots). More paint on the brush will give you big, solid dots, less paint will give you light, speckled dots that look almost like dry-brushing. It really depends on what effect you’re going for. If you’re creating rust, lichen or moss, start with big, close-together dots in the middle of the rust patch, and then use thinner dots around the edges so there isn’t a clear line between the feature and the base texture. Same goes for shading the space in between bricks – big dots to emphasise emphasize the actual lines, thinner dots to create more subtle shading.
This is an excellent technique for features (moss, lichen, rust, etc etc) and detailed shading. It can also be used for large base textures, but this will take ages and drive you insane.
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This technique, as the name implies, involves texturing with a brush so devoid of paint that it’s almost dry – or rather, the layer of paint on the brush is so thin that it is dry immediately after being applied to the surface.
This creates a far more subtle texture effect than stippling, is often used as the next layer up. Stippling on its own (especially for stonework) can look a bit obvious and high-school: adding dry-brushing can give flat surfaces another layer of texture and griminess. It’s good for shading, and also for dulling out colours colors that are too vibrant – a good light-grey dry brush over a surface can give it a nice dusty, aged look. Dry-brushing onto shiny metallic surfaces is a good way of dulling them down and making them look aged (as well as not bouncing the light).
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Glazing involves watering down paint until it is basically tinted water, and staining surfaces with it by washing it across them or letting it drip down them. This can be done with sponges, sponge brushes, paint brushes, old dishcloths, clean paint rollers...anything that can absorb water.
Always have at least two shades of glazes for each surface you’re working on – this will emphasize the texture and ageing of the surface. Choose glaze colours colors appropriate for the base colour color – brown glazes for sandstone shades, black glazes for slate shades.* Since the wash is so thin, you can even glaze in brighter colours colors (red, green, blue, orange) to tint a surface.
To lightly tint a surface that’s too bright or flat, wash the glaze over the surface with a large sponge or roller. Be careful not to let too much of it collect at the bottom, or it will make everything soggy. Mop it up regularly! Water gathering for too long on plywood can even make it warp and bend.
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