Vinegar is one of those all-purpose ingredients that's tough to live without. It's as great on a salad as it in 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 (50/50) 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.
Up next: When mixing your glass cleaner, go small.