When you decorate your home you can use a variety of painting techniques to give different effects. Start by painting a base color on your walls and then apply a glazing top coat. Have fun experimenting with the various techniques on a painted board before deciding which ones you want to use on your walls.
Once your base color is dry, you can literally wash the walls with color. Mix a tube of student acrylic paint in a half bucket of water. Lightly dip a sponge in the paint solution and wipe it on your wall, exactly the way you would wash the wall with soap and water. You can use a wallpaper brush to spread the color further and you don't have to worry about the color being even. In fact, having slightly more color in one place than another actually adds to the effect. One of the great things about this technique is that it's very quick, easy and cheap, so it is ideal for those on a low budget or without a lot of time to spend decorating.
Rag rolling is quite time consuming but allows you to put a textured effect on your walls, depending on the type of cloth you use for your rag. Once your base color is dry, apply your top color with a rag. Either use a thinned down regular paint or a translucent glaze color designed for special effects. You dab the rag in the paint and then dab, pat or roll the paint onto the wall. Scrunch or roll your rag on the wall in a random pattern. When your rag needs more paint, scrunch it up in a different way, then add more paint, and continue. Keep doing this, changing the way you roll or scrunch the rag as you apply more paint to the wall. If you have the patience, as long as you allow each coat to dry, you can rag roll either one or two more coats on top of the first to create a mottled effect.
Using another similar technique, called ragging off, instead of putting color onto the wall, you first put on the glaze coat on the wall and then use your rag to remove the glaze, revealing the base color underneath. If you prefer, instead of using a variety of rags, you can use a crumpled plastic bag or saran wrap to reveal the base coat. Unless you are working with a partner who applies the glaze ahead of you, apply the glaze in small sections, and work quickly to remove it.
Another way of creating a mottled effect is to use a stippling brush. Apply the top glaze color in the same way as for rag rolling, and then remove the color with a small stippling brush. Moisten the brush with the glaze and then firmly apply the tip to the wall, keeping the brush at a right angle to the wall. As you remove it, some of the glaze will come off, revealing the base color underneath. Keep repeating until you have stippled the whole wall. Make sure to use the same amount of pressure all the time and wipe the brush occasionally with a cloth to prevent the bristles from clogging with paint. Alternatively, you can reverse the technique, dabbing the glaze color directly to the wall with the stippling brush, which will create a slightly different effect.
Contrasting base and top coats will give a dramatic effect, while using complementary colors will give a more subtle look to your room.