Go distilledMost of us don’t consider what’s in the water we use to clean. In truth, it usually doesn’t matter. But with glass, you see absolutely everything, so water content can make a difference -- especially if you have hard water.If you’re diluting your glass cleaner, consider using distilled water. It doesn’t have all the minerals in it that can be present in the water from your tap, so it won’t leave behind any streaky deposits on your bathroom mirror. Of course, the cleaner you’re diluting matters too. Vinegar is your friendVinegar is one of those all-purpose ingredients that’s tough to live without. It’s as great on a salad as it is on your mirror, and it costs practically nothing.Whether you’re out of your usual glass cleaner or you’re just looking for a cheaper option, vinegar can do wonders for your windows and mirrors. A vinegar-water solution works great - just spray or wipe it on like you would any other cleaner.The smell will stick around for a bit, so if you gag at the scent of vinegar, you might save this streak-free cleaner for outdoor glass.Minimize sudsThere’s nothing like a bunch of suds to leave your glass full of streaks. This isn’t a problem if you’re using vinegar or straight glass cleaner -- no soap there. But if your coffee table is truly dirty and you’re adding soap to the solution, remember: go easy.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.And speaking of residue: It’s perhaps the biggest glass-cleaning mistake many of us make.Banish paper towelsYou know that bucket of glass-cleaning supplies you carry through the house when it’s window day?There should not be a roll of paper towels in it.Paper towels leave not only streaks, but linty ones. Instead, go for a microfiber cloth, a squeegee, or best yet, a handful of newspaper. Your morning read does an amazing job on glass.If you go with the newspaper, be sure to wear gloves. That ink gets everywhere.Buff itEven if you do exactly the right things, you can still end up with a streak or three. In that case, the simplest solution is to finish the job with a quick buff.A chamois or a microfiber cloth is best, although a regular rag will do. Keep it dry, and just buff over the glass when you finish cleaning it. You’ll find those streaks just disappear.As always, keeping up with the job makes it a whole lot easier. The less dirt and grime your windows accumulate, the less time you’ll spend cleaning them -- a quick vinegar spritz, newspaper swipe and you’re on your way.