I have a special blue microfiber rag that I use to wipe off all of my devices every single night. I fold it into fourths, get the corner wet, then wring it out until it's damp, and start wiping my devices. Then I grab the dry side and dry it off immediately, making sure to not leave streaks or any smeared oils. Once that's done, I plug it in for the night, making sure to not touch the screen again until the morning.
I wipe my iPhone off like this at least 2-3 times per day. I know I have a problem