We need to position skips to within a few (~10?) cm on level ground. I've seen positioning systems for roll on/off containers, these were horizontal guide rails on the ground and presumably the container is pushed between them.
Skips are lowered onto the ground from above:
At first glance, a few bars jutting from the ground at an angle (to form a funnel) could do the trick. From looking at videos the skips swing when beeing set down. The bars would need a coating with PE or a similar soft(er than metal) and tough material.
I don't want to invent something as I'm sure this is a solved problem. So far my googling hasn't brought me to a solution. What to do when your skip needs exact placements?