Surely Henry's picture should show the horizontal axis of the roll set at some 10 - 15deg above the horizon so as to cope with the inevitable fall through that would otherwise require the recovery action so clearly pointed out by NigelOnDraft.
The way I was taught in the Bulldog was to be aligned on your chosen line-feature, drop the nose and bank 45' away from the direction of intended roll, then reverse the direction of roll into the maneuvre and commence the pull, thus establishing on the profile at the half past four or half past seven point,nose lowand rising with 45 deg bank and ensuring that wings level occurred at least 10deg above the horizon. That in turn should ensure wings level inverted on the other side and still with nose appreciably above the horizon - or else chuck it away as NOD describes. The BIG briefing point was nose 10' above the horizon at wings level pitching up to ensure a safe pitch attitude when inverted.
It might be different in a fast jet, but that works in a light single, or at least, as I recall it.