Worked as a Commercial Glazier for 20+ years and have cleaned more glass than I care to remember. We always used, exclusively, a readily available glass cleaner called Sprayway. We used paper towels but if you do use paper towels use the blue lint free kind. A squeegee is best if you can find a small one, like for a bathroom shower. And never use a metal razor blade to clean glass unless you have some soap solution on the glass or you will scratch it. Plastic blades are available, they wont scratch glass but are not very durable.