King Pin

I use a red "remove before flight" flag hanging from the pin.
Some times we have camped on a slope with the back of the trailer close to the ground and the pin head high.

Pool noodle pieces and a bungee cord is what I use

Can coozie as well on pin itself. Took a hollow pool noodle, cut into 1' strips, cut lengthwise to center/hollow section, slide over the small lips on hitch.

I have a locking sleeve on it that has an orange flag hanging down. Gives a little notice it's there.

I would just put something on the ground under the kingpin. A bucket or tote or something.

^ we do this as well sometimes.
an incident I was involved in was not the kingpin but the edge of the trailer near the kingpin. I was doing whatever and turn toward the trailer and all I saw was a flash of light and pain. Hit the right side of my forehead on the edge of the trailer when I was going under to get something from the front compartment. Nice bruise on my noggin. I still don't know what I was thinking, I knew it was there, had been under that thing 20 times right before it. Just did not duck enough that one time. It hurt.

I, too, use the natural selection approach.

You could hang a curtain around the pin box. All people need is some sort of visual reference and they'll steer clear.

I'm trying to convince the folks at AirChair.net to make me one that mounts to my kingpin.

I've seen this somewhere. Some company does offer it but I don't like the fact you have to screw snaps in the sides of the trailer. Maybe some strong Velcro straps could do the same without making all the holes.

Not the same as just around the pinbox but it would be kind of nice to have that area isolated from eyes. Of course nothing secure about it. Just an out of sight thing.

I purchased a small orange traffic cone from Lowe's and used a couple of bungee cords to hang it upside down (with king pin in center of cone)over the pin.