In reply to Silum:
Is that the direct start into Elegy (A little Peculiar)?
Personally I'd say the difference between a mantle and a rockover is mostly to do with hand/foot relative height and position. For a mantle they're basically all in the same space (hands and foot). For a rockover the foot is a way out to the side and (often) a bit lower.
OP: Go do laps on Bob's Bastard and the slopey shelf round to the right of Morrell's Wall until your wrists are ruined, that should sort your basic mantleshelf technique
http://www.ukclimbing.com/logbook/c.php?i=28580
jk