Select a cutting method for cutting glass according to the shape of the cut that you want to make. Straight cuts can be made with a scoring tool. Compound intricate cuts should be made with a glass-cutting wet saw or by a professional glass shop. For straight cuts, use a glass scoring tool. a) Measure and mark the tile with a marker on the top of the glass tile where the cut must be made. Run your finger along the surface of the glass where you plan to score before marking to remove any particles that could affect scoring. b) Applying light oil (WD-40 or even cooking oil) to the scoring wheel will help achieve smoother scoring lines. Apply pressure to the glass as you pull the cutter along the surface, rolling on the scoring wheel. The score must run from one edge of the glass to the other edge. c) When scoring, a gritty sound means that you are pushing too hard. A smooth, tearing sound is what you want. Score along a straight edge. Use a metal ruler or straightedge. d) After scoring, the tiles can be broken on a table. Place a soft cloth or cardboard on the table to prevent damage. Place the tile, finished side up, with the score along the edge of a table then push the part to be cut downward. You can also just grip the glass firmly, one hand on either side of the score. Then use a snapping action with your wrists to break the glass. e) Use fine sandpaper or emery cloth to smooth and debur sharp edges resulting from glass cutting. Be careful not to scratch the finished surface of the glass. Follow all safety procedures, including using safety eyewear and protective gloves when using scoring tools and cutting glass. If compound or notched cuts, around an outlet for example, are required, you may need to use a wet glass-cutting saw, available for rent from most home centers. In many cases, cuts that you cannot make with a scoring tool can be easily done by a professional glass shop. Remember to mark your tiles for cutting first.