Sketch your design onto the surface you want to add mosaic to, with pencil or a marker. The surface can be a table top, flat plaster board, wood panel or glass globe. You can also work from a premade design. Alternatively, transfer a design onto the surface by tracing over the image on paper with a graphite pencil, then place the image over a piece of carbon paper on the surface, and trace over again with the graphite.
Use a ruler or other straight edge and measure out evenly spaced tic marks, horizontally and vertically, for a grid. Use the pencil to draw out straight lines against the straight edge.
Decide on the tile colors you want to use for your project. Separate these out into piles according to color and design. Depending on whether you are using glass tile or mosaic tile, use the glass nippers or mosaic tile nippers to cut the tile into shapes that will precisely fit any irregular shapes in the design, such as leaves or fins.
Put on latex gloves, and place a dab of adhesive on the back of each tile just before laying it down. Use an adhesive appropriate for the surface you are using. Lay the tile for irregular shapes first. Then lay any square tile into the grid, one color at a time, to arrange an evenly spaced pattern. Use the tweezers to shift tile that moves out of place. Cut the tile surrounding the irregular shapes with nippers. This step is saved for last so that irregular shapes are clearly visible. Allow the adhesive to dry overnight.
Mix 1/2 cup of grout with water at a ratio of about seven to one, or a tablespoon at a time until the consistency is thick and creamy. Gently spread the grout over the tile with the grout spreader tool, ensuring that all crevices are filled. Spread the grout in one direction across the entire piece, and then spread in a perpendicular direction, to fill the crevices completely.
Let the grout dry for 15 minutes, then wipe excess from the surface with a sponge dampened with cool water. Allow the grout to dry overnight. Use tile and grout sealer to prevent moisture damage and yellowing.