I use prop savers on a lot of my planes. I’ve had bad luck with o-rings, so I know generally use a small slice of surgical tubing to hold the prop in place. This works great except … it’s really tight and fiddly to get the o-ring / tubing in place over the prop. I’ve used hemostats, pliers, small screw drivers. They all suck.
About a week ago, I had an idea for a different tool and, while looking for materials in a drawer, found some picture hanging hardware that I thought would work for what I had in mind. I built a prototype tool and it works great. Here’s what I did.
I started with a cheap picture hanger, like one of these. My original was made from a thinner picture hanger than these, but these work fine. They cost $0.97 for a 3-pack.
I straightened out the hook part that’s designed to hold the wire on the back of the picture.
I flattened mine out in a small vice, but pliers or a hammer will do.
Here’s the shape at this point.
Next, I add a new bend in the opposite direction from the original hook. This will only stick out 1/8″ or thereabouts. 
Here’s the final shape.
I added a sort of handle by putting some shrink wrap about the lower portion of the tool.
Here’s the finished tool. My original is at the top. 
I’ve found this to be nearly perfect for grabbing onto my o-rings, etc., pulling them into place, and then letting go of them again.
