Use a screwdriver to remove the cabinet areas you want to stencil stain, if they are currently mounted. Place them on a flat surface or sawhorse in a well-ventilated area. Protect the floor and workspace with a drop cloth, some old newspaper or flat cardboard.
Lightly sand the surface of the cabinets with sandpaper if the wood is new or contains scratches that need to be smoothed. If the wood is already stained, clean the surface with degreasing cleaner to remove any residue.
Place the stencil flat against the surface where you want the design to appear and secure it with masking tape. Use multiple stencils to create a repeating pattern or to complete additional designs while the first one is drying.
Load the brush or sponge with a small amount of gel stain. Wipe off any excess stain using a clean rag. With the semi-dry brush or sponge, apply the stain to the surface, beginning with the edge and working your way in. Consult the instructions on the stain's packaging to determine how long you need to leave the stain on the surface before wiping it away.
Wait for the stain to dry completely. Remove the stencils and screw the cabinets back into their original positions.