Dried out my B36 (2002) two weekends back, and took the main halyard across to a strong point ashore in order to ensure that the boat maintained a lean towards the wall. You do need to keep a careful eye on it as you go down in order to maintain the lean, and particularly once the tide has come back in and you start to float where you then need to slacken off and the halyard and bring the end back onboard. We cast off as soon as we floated, and headed back to our usual mooring.
As for choosing a level area, we weren't able to select one, there was wasn't one around and as a result we settled with the bow slightly raised. If I had to do it again I'd turn the boat around first.
We also disconnected the hand rails on the side in contact with the dock wall/piles, and lifted out the handrail stanchions to prevent them from being damaged. Also we put our fenders out on the side next to the wall to protect the hull gel coat.