Soap is king if you're looking to work up a nice lather. However, when used incorrectly, suds will only leave glass surfaces covered in ugly streaks. If the task at hand truly necessitates a deep clean, be sparing with the amount of soap you add to the solution. A little bit goes a long way!
It doesn't take much soap to get rid of that dirt, and using too much will result in an overly dense cleaner that can leave a streaky residue on the glass. To concoct your very own batch, simply mix up 2 quarts (1.9 liters) of water with 2 quarts of rubbing alcohol. Then add three (that's right – only three) drops of liquid dishwashing soap to the mixture [source: Mrs. Clean].
If you're not against chemicals you can substitute sudsy ammonia which is already mixed with the right ratio of soap. In that case, mix 1 ounce (29 milliliters) of soapy ammonia, 4 ounces of rubbing alcohol and 3.3 cups (780 milliliters) of water [source: Cleverly Simple].
Do some experimenting to find the right formula that works for you. As with any homemade glass cleaner, pour your mixture into a spray bottle, label it, and keep it away from children.