Tailing loops bug the hell out of me. They seem to often result from trying to hard on the final forward cast. I know pretty much why they happen, just can't seem to break out of the mode sometimes.
As far as clocks and drift go, from what I've heard...
Other than trying to get someone off the ground with casting I think Lefty's got it right. There ain't no clocks in flyfishing. The stopping points are to be abrupt, to unload the rod, preceded with the smooth acceleration of the rod, to load the rod. At the risk of mis-representing Roberts, for distance casting, rod drift, after unloading on the backcast, is a means of providing a longer stroke through which to accelerate and more deeply load the rod. So I'm not sure why drift is nessacerily a problem.