As a rule, knock on the door, or use the doorbell / door-knocker . . . and then get off the front porch and stand back on the sidewalk at least 10 ft away.
Yeah, standing a few feet away is necessary just do the door peephole can work. Entering a house without giving the occupant an opportunity to vet you is just stupid.
As to opening a screen door, that is common in many areas. Knocking on a closed screen door sounds horrid, threatening. Opening it and knocking on the wooden door frame is a lot less threatening. Just standing there with the screen door in your hands is back to being threatening.
“As a rule, knock on the door, or use the doorbell / door-knocker . . . and then get off the front porch and stand back on the sidewalk at least 10 ft away.”
That’s what the police in Farmington, NM did just before the homeowner opened the door with a gun in hand and then aimed the gun at one of the officers. The police promptly shot him dead