I usually just run a single line from the steering to the cleat on the dock unless there is a bunch of boat/wave action not much more is necessary, I try to tie off on the lee side of the current so that the water isn't pushing me back into the dock and scuffing things up. If I end up on the wrong side then a 2nd line is helpful to make sure that the hood or rear don't slide under the dock, learned the hard way due to scratches.