You don't have to get your feet wet provided you plan ahead first....
I normally put the hook at least half way down the trailer before putting the bow of the boat onto the first set of rollers, hook up, turn off engine, and then very carefully climb up the trailer to the winch. One day it'll catch me out and I'll get wet, but for now, it works just nicely
Try and make sure any weight you have on board is central and the boat is level before winching - if it's slightly out, the boat will lean over as its being winched up.
-Alex