Measure your foyer floor. Sketch out the size to scale on graph paper. Decide on a design, whether it's 12-inch square tiles or a decorative mosaic. Use colored pencils if you want to make multiple colored faux tiles and color in your design.
Remove existing floor covers from the foyer to get down to the bare floor underneath. Depending on your home, this may be wood, plywood or concrete. Clean the floor thoroughly with a scrub brush and household detergents. Mop it and let it dry.
Prime the floor with a shellac primer. Shellac is an excellent sealer that dries very hard and quickly. Allow the first coat of primer to dry then apply a second coat.
Paint your floor a base color with a flat or eggshell finish paint and let it dry for a day. The base color will be the color of the faux grout lines in your tile.
Use a ruler and painter's tape or masking tape to transfer your planned design from your scale diagram to your floor. The tape will cover the faux grout lines and define the shape of the faux tiles.
Paint your faux tiles the desired base color with a satin finish latex acrylic paint. If you are making all the tiles the same color use a brush to cut around the edges of the floor and use a roller to cover the bigger expanse of floor. If you want your tile different colors or are making a mosaic, use a paintbrush and paint each individual tile by hand, referring to your master diagram to put the proper color in the proper place. Let the base coat dry.
Brush or roll a glaze over the faux tiles to make them look like glazed tile. For an old-world, natural look, tint three parts glaze with one part paint in a slightly darker shade. Instead of applying it with a brush or roller, dab it on lightly and randomly with a slightly damp sea sponge to give the floor a muted, rustic stone appearance. Let the glaze dry.
Remove the tape to expose the grout lines. Let the floor cure for up to 30 days, and avoid walking on it or putting furniture on it if possible. Keep it dry.
Top the paint job with two coats of clear polyurethane as per the manufacturer's instructions.