Aerial Refueling I am assuming

Not sure how Fred handles behind the tanker, but off the top of my head, here are some tips we used in the Herk:

Though in the C-5 you don't have the instant power gratification you do in the 130, as well as much more momentum issues to deal with, make sure your corrections are small (especially in the thrust regime), wait for the result, and anticipate when that correction is no longer needed (lest you have to make another correction). Your inputs should be small enough that it seems you have to only think about it, rather than big yoke/throttle inputs.

Fix one thing (vertical, lateral, or distance) at a time. Of course, as you get better, you'll be able to fix more things simultaneously.

Use the wings of the tanker as an "ADI in the sky."

If you find yourself doing the "I can see the tanker's tail #" PIO, just stabilize yourself out to one side for a few seconds, then slowly make your bid back to centerline.

If you are only a bit outside (i.e. still between their inboard engines), we would use their jetwash to keep us from moving any further outboard. In other words, if you were drifting slightly to the right, you could keep that right aileron in and hold the plane laterally stationary against the jetwash. To move back to the left, take out some of that right aileron. This may or may not work for the C-5.

I think once you get good at pre-contact, actual contact is not too tough to pick up.

HTH!