Never use a towel that has ever been used to remove polishes/waxes/sealants/dressings to clean glass.
Have dedicated towels that are washed and dryed seperate from the other towels. Do not use fabric softener in the wash either, the silicones transfer to the towel and then the glass.
Best are used, clean "huck" or "surgical" towels, although Micro Fibers will work very well, just expensive, save them for the paint.(if you get new surgicals, wash them at least twice to remove any "sizing" that is in the material as it can release and cause streaking as well) Also, this keeps you from getting them confused.
Use two (2) towels, folded into quarters.
The reason for this is the same as when wet sanding, EVEN CONTACT with the glass.
Mist ALL the glass you are cleaning, do not just shoot a stream at one spot and then move it around. (one of the reasons some think the aerosols are better, it gets on more glass)
Allow the glass cleaner to have a few seconds to break down the film and dirt on the glass.
Agitate with one folded towel in striaght movements, not circular.
Then, using the second towel, remove the wet film in striaght lines. If you feel the towel "sliding" , not grabbing on the glass, you have missed a spot. Feel sliding and you will have a smear or streak.
This is the system I developed over 14 years ago for the car companies large pre-delivery centers and we still use today in our own centers.
On any given week day now, the employees are cleaning the glass on 200 plus vehicles and the dealers are very happy.
Just give it a try, think you will be pleasantly surprised.
:up