Practice first, then tackle your project

Here are tips to get you started in stenciling.
UPractice on paper. This will teach you how the stencil works and how the colors are going to look.
If blotches appear or the paint seeps under the stencil, you are using too much paint.
To remove excess paint from the brush, dip the brush into the paint, then swirl it firmly into a stack of paper towels using a circular motion. Very little paint should be left on the brush.
Your design will look more interesting if you blend colors on the painting surface. For example, rather than stenciling a leaf with just green paint, start with yellow, then shade with green, then shade some areas with red.
If you have stenciled a pattern and the color is too bright, tone it down by shading lightly with a complementary color. A complementary color is one that is opposite on the color wheel. For example, if you have a bright orange flower, shade lightly with blue. Do this sparingly, however, or the color will turn brown.
UBring a fabric swatch or sample of your room colors when you buy paints. That way you can match the palette as closely as possible.
The base color of the surface that is being stenciled might affect the the stencil paint colors.
If the surface is anything but white or off-white, test your stencil colors on a painted piece of poster board. If you are not happy with the results, stencil first with white paint, gesso or latex primer, then add the stencil colors.
UUse blue painter's tape to attach the stencil to the surface. You will be able to move the stencil around several times before changing the tape. Painter's tape won't pull paint from the wall or leave residue like masking tape.
If you are using a stencil that has several layers, be sure you mark the registration so that layers are easy to place.
There is usually an alignment hole in the stencil for marking the registration.
Most important, have fun and enjoy your project. It's only paint.