Select a frame that is flat and fairly wide. Prime the frame with a primer formulated for the type of materials your frame is made out of. If the frame has a glossy surface, you may need to lightly sand it first.
Apply two coats of medium-brown latex paint in smooth, even strokes. Lightly sand the frame between coats.
Mix the glazing medium with a small amount of burnt umber and raw umber tints to create a color that is slightly darker than the brown base. Pour a little of the glaze into another container and add additional burnt umber, raw umber and black to make a slightly darker glaze.
Apply an even coat of the lighter glaze to one side of the frame. Use a 1-inch brush to add additional short strokes of darker glaze in various directions. Smooth out brushstrokes by lightly dabbing with a soft ball of cheesecloth.
Place a sheet of 100-grit sandpaper with the front facing down, perpendicular to the bottom edge of the frame. Pounce the stipple brush along the edge of the sandpaper to create the look of distinct squares of leather. Remove the sandpaper. Stipple the entire side, allowing some variation in color to remain.
Glaze each side of the frame using the same process. Vary the placement of the sandpaper for a more natural look. Protect the first glazed side when glazing the final side with a sheet of 100-grit sandpaper.
Spatter the entire surface with a small, round brush. Dip the brush into the darker glaze and shake off excess paint. Gently hit the metal ferule of the round brush against a solid, wooden paintbrush handle to disperse fine droplets of paint onto your faux leather surface. Gently dab the surface with cheesecloth if the spatter looks too obvious.
Allow the frame to dry completely. Follow the directions on the frame to install the mirror within the frame securely.