What I found works best and nothing has changed my mind is my moms system.
Using crumpled newspaper ,the kind that comes in your driveway for free, the cheapest paper and printing that smears on your fingers, the more colour the better.
wet windshield with pure ammonia dilute with water ( i refined this to de-ionized water) 30% ammonia the rest water.
Spray on and dry with the inky news/flyer paper ,wipe until it squeaks .
No soap because that is what streeks,the ink is a micro polish.
works or I'll refund your money