Warren,
I think we are talking about the slowest of speeds approaching the dock, and the boat stationary when disembarking. Those flying leaps of gallant pirates would end me up in the drink or the emergency room. Very very slow, very deliberate, controlled stepping off the boat - if that's possible.
Of course, being tied in place before disembarking is the safest route, especially in rough weather, high winds/current, etc.. My aim in docking procedures nowadays is to be as slow and boring as possible - no feats of daring involved, no quick movements.
My preferred float approach is to reach out the helm window, or the aft helm, and engage a spring line from that cleat just forward of the helm window to a cleat or post on the float located just forward of the stern position, and then to gently power forward on that. That will give you control and minimum surprises, but it's not always easy or possible to do.
For years I have stepped off with one or both lines in hand, but I've slipped twice this year on wet, mossy float boards, so if I'm going slow enough, I prefer to toss the lines from the cockpit to near where I'm planning on tying them and then use both hands to securely step off the boat onto the float. This is the first summer I've started that. I have some new scars and bad memories about the two times I've slipped stepping off onto a wet slick surface without a secure handhold.
To all you young, adventurers, like Warren, I suppose you could put one rope in your teeth, your saber in one hand and the bow line in another hand and leap into infamy!!!! JJ
Marty, having that rope already tied up like you mention would be a neat idea if you're talking about a slip to which you return often.
I sometimes keep a rope from the forward cleat to the aft cleat with a large loop tied in it at about the aft cabin corner and so I can gently place the boat in position and just slide that loop over the float cleat. 'Works great for most fuel docks. Not all places have a cleat in the preferred position, though. That setup would get you maximum control with the least risk to my mind.
John