Want to be an awesome artist who thinks outside the realm of the norm, an artist who scorns those who use oils and pencils and charcoals? Use nail polish!
Nail polish cannot be used to create a detailed picture with hundreds of shading. Instead, you must cut the image down to only the basics. You don't draw what is there, you draw what you think should be there. For that reason, drawing people, faces, and anything that needs shading and delicacy should be avoided. Pictures of movement, familiar pictures and vague pictures are better. I tend to use my nail polishes for seascapes.
The surface which you use cannot be paper. Paper tears as soon as you try to work with polish in the sticky stage, and it also crinkles as the polish dries. Magazine paper is an easy surface to apply polish too. I wouldn't suggest canvas or some other sort of non-shiny material, but that is up to you. Lacquered or painted wood is also an excellent choice.
Nail polish is very difficult as a medium to use due to its drying time. If the nail polishes are ones that you are familiar with and use on your nails, you should be fairly knowledgeable when it comes to their different stages in drying. The great thing with painting a picture with polish is that all three stages come in handy.
In the wet stage, colors can be mixed to create an entirely new color, just like you would with paint. The color should be mixed on the surface it is meant to cover and shouldn't be mixed with the nail polish brushes. Cotton tips, paint brushes and rolled up tissue should be used instead. Cotton tips can be used until the cotton begins to roll off and stick to the nail polish. Paint brushes can be used until they die, and tissue should be used carefully because bits of tissue will come off if it was used during the sticky stage.
The sticky stage is when you layer things, but also sort of mix them. You don't want a new color, but neither do you want them to layer over each other.
Layering comes in at the dry stage. In this stage, you have applied a polish, waited for it to dry and then added another polish. For example, you paint gold polish and wait for it to dry, and then smear a thin layer, spreading it out with a cotton tip, over the top. This has created the shore of the beach. Care has to be taken to ensure that the polish is not still sticky. As soon as you apply wet polish to sticky polish, a totally new effect occurs, but probably not one that you want.
Should you make a mistake, use nail polish remover. Dip the cotton tip into the remover and carefully dab it onto the part you want removed. Do not rub it because otherwise you will affect the surface below. Take a clean cotton tip, or even better, a tissue, and dab at the remover that is now on your surface. This will soak up the remover. Wait for it to dry, and you will be able to cover the area again with polish.
Have fun and happy painting!