My boat had hand-holds drilled through the top board of the boom gallows on each side, and I had a line knotted around the hand-hold and hanging down with a bowline loop in the end at just the right height. I'd raise the tiller to clear the Sampson posts I used for mainsheet cleats, and drop the loop over the tip of the
tiller.
This keeps the tiller to one side and out of the way, but it doesn't lash it fast to the stern pulpit, which I don't think is a good idea. When a wave or a wake hits your boat, your rudder will want to wiggle, and if it is free to do so, a little bit, then it will absorb a lot of the wave action. If the tiller is lashed tight,then the rudder won't move and the whole boat will rock more.
Sorry, no photos.
