an easy system to encourage manual flying would be where we have to perform and record a certain number of manually flown, raw data manual thrust approaches every six months, as part of normal line flying.
Not a bad idea, though it sounds a bit like the good old military days of "chasing the line"...and the "pencil whipping" that just might have gone on...
Playing Devil's advocate for a moment what would be an acceptable level of, say, hand flown approaches (define? e.g. autopilot out below 3k??)) per six months? I know at times some F/O's on Longhaul Fleets struggle to get a landing/approach of any sort a month, due to the heavy crewing they are rostered to do.