Marble can be achieved by using a thick plastic garbage bag. The finished look, gives a marble appearance, so when choosing your colors, look at authentic marble for a natural set of colors what would work in your home.
The following technique was gathered from Susan Driggers Painted Finishes For Walls & Furniture
This technique involves 2 basic steps. To achieve a greater depth in the finished product, take the second step and repeat it adding more glaze and less paint. The key to this faux finish is the glaze which gives a transparent finish.
1. Paint your wall in a soft beige white. Look at natural marble and pick the best color as your base coat. Let the wall dry.
2. The next step is adding the glazed paint which will be applied on the wall using a garbage bag.
Take a pre-mixed glaze of a darker color of your original color. Yellows or shades of white with a bit of brown work well. Work again with colors you find in marble. Work in small sections to make it look like big slabs of marble. Tape off large squares on your wall to break up the pattern.
Take your paint roller, and roll on the glaze in a section of the square you are working in. Let it dry a slight bit* Take your heavy weight garbage bag, and press it on to the wall. Run your hands on the garbage bag, allowing the bag to be pressed into the paint. Don’t move the bag around, just simply roll your arm or hands on the bag, allowing the bag to stick to the wall. Simply take off the garbage bag, and your left with a crinkled print on your walls.
-Be sure to clean off the paint mess in the next square when you are done.
-To create the marble veins, you could simply take a small paint brush and use brown paint and mostly GLAZE, and paint in the small veins found in marble ON THE WALL. Take your garbage bag, and roll the glaze on the garbage bag, and press it on the wall.
-Marble has milky layers to it. So if you are adding additional steps, allow your glaze to be a bit of a milky white brown or yellow mixture. Additional steps should be more glaze and less paint, because you do not want the original pattern to be disturbed much.