I do not use Windex (ammonia) because that can yellow the screen. I used just water for years, but a film built up.
For the last 6 months, I put a drop or two of "green" kitchen dishwashing soap (not Palmolive or like) into a well-laundered J-cloth (we keep them in the laundry room). I suds up the cloth, rinse most but not all of the soap out of. I wash the screen and the keyboard. I rinse the cloth until clear and wipe off the screen and then the keyboard. I now do my iPhone at the same time on the way by.
Zero streaks. Do it with the monitor off and black and all the final wipe of water to evaporate on its own. You will see a perfectly even screen.
Great tips. I guess because you don't wipe OFF the FINAL wipe, there are no directional marks/ smudge appearances.