1. If ammonia doesn't get rid of a chemical build up in your glassware, smear the glass surface with Vaseline (petroleum jelly) and leave overnight, or longer. Then wipe off and wash clean.
2. Methylated spirits rubbed on the outside panes of your windows will make them shine in a way you've never seen before. It will also bring out the iridescence to produce a blaze of sparkle and color.
3. Many people have reported having great results cleaning their glass using toothpaste. I wouldn't like to recommend any particular brand, so try a few and expect good results.
4. Efferdent tablets, which are used for cleaning dentures, are very effective in cleaning glassware. They contain a solid form of peroxide, which performs the cleaning part. Fill your glass with water and add two tablets. Let stand for an hour or so and rinse out.
5. Citric acid will clean glass and make it shine. To produce a concentrated solution, reduce pure lemon juice in a saucepan on the stove to half its volume. Use the cooled liquid on stubborn spots, letting it lie on the surface for at least an hour, then wipe off.
6. Vinegar diluted with a little water can be very effective for cleaning glass. If your glassware has difficult to reach areas, use a small soft haired artists brush.
7. Don't clean your windows when the sun is shining brightly. It will dry the panes too quickly, leaving streaks. Wait for a dull day and you'll get better results.