Ensure that there are no creases in your stencil so that it lays as flat as possible. As an extra precaution, you could place the stencil on top of a flat, hard surface and then cover it with something heavy, such as a large book.
Align the stencil on the wall or object. Make sure that the stencil is straight by marking its position with chalk line, especially if you are stenciling on a wall.
Affix the stencil to the wall or object with spray adhesive or masking tape.
Decide which of the three paint application methods you prefer: brush, sponge or roller. Experiment on a piece of white poster board before applying the paint to the wall or object.
Remember that the real trick to stenciling is applying the paint sparingly. The brush, sponge or roller should be more dry than wet, unlike when you paint a wall a solid color. A little bit of paint goes a long way when you stencil, and you don't want the paint to drip behind the stencil and ruin your design.
Pour puddles of paint in the paint trays or on the paper plates.
Dab the stencil brush into the paint. Remove any excess on the paper towel. You can move the brush from side to side within the cutout areas of the stencil, swirl the paint around or use a technique called stippling. This is when you repeatedly pounce the surface to create a soft, muted paint effect. Stippling works best on very smooth surfaces because it will reveal surface imperfections.
Alternatively, dab a small sponge into the paint and remove any excess on a paper towel. Apply the sponge lightly to the stencil, either by dabbing it gently or stippling. Either way, you will clearly see the texture of the sponge -- an effect that won't result from a brush or roller. Just as with a stencil brush, you may use one paint color or multiple colors to create a two- or three-dimensional effect.
If using a roller, load it with paint and remove the excess by rolling it on a paper towel. Apply one color or several colors to add depth and dimension to your wall or object. Applying the paint thinly will result in some of the base color showing through; applying greater pressure to the roller or applying two thin coats will create a more vivid effect.
Carefully remove the stencil from the wall or object after the paint is completely dry.