Spray your quality glass cleaner on heavy. Let it stand for at least 30 seconds to break down the crap, then wipe and follow with second towel as noted above.
For towels I use waffle weave MF drying towels.
Meguiars D120 glass cleaner concentrate is about $20/gallon. It will make 11 gallons. Add in the cost of 10 gallons of distilled water which is under a $1/each.
Your cost is $3/gallon for a quality glass cleaner.