Today was a day for gear changes and roundabouts, some dual carriageways and national speed limit single carriageways in the pitch black freezing cold. Kev was trying to get me more confident and less slightly dangerous on roundabouts which is good as I find them shockingly confusing, particularly if I need to do a gear change coming up to them.
Lifehack has an article on making decisions under preasure, which I think probably covers the broad techniques I should be using to make sure I am better at roundabouts than I am at the moment.
Specifically - know the situation, know the outcomes and commit to the task at hand.