I don't think I'm aloud to answer that really Richard in case a courser is reading. OK all you five day course guys promise too look away now.
Right now it's safe to talk, I firstly drop a screed down the right hand side of the wall and then if the wall is no more than about 12ft long I drop a screed down the left hand side, or if the wall is longer I drop a screed down the centre of the wall, then I drop back to the top right hand corner and render right across to the left hand screed but only coming down the wall about 18in to 2 ft at a time before ruling from screed to screed and then working down the wall using the same technique. I know it probably sounds like a lot hassle but when you are used to the routine it is a very quick and more importantly accurate way of rendering, and because you are always ruling off fairly small areas at a time the muck you remove with the feather edge is still wet enough to go straight back on the board and be put on again.