"Most people can ride fairly quick but not many cannot ride slow" is what I tell students from CBT up to full test.
Look where you want go.
Slipping the clutch is ok.
Learn to drag only your rear brake to control the bike.
Don't use the front brake at all for slow speed work until you've mastered using the rear, even then it's much more effective to use the rear.
With this technique you should be able to perform full lock turns with the wheels barely turning, even momentarily stopping them if you want to get cockey
Look where you want go.
Slipping the clutch is ok.
Learn to drag only your rear brake to control the bike.
Don't use the front brake at all for slow speed work until you've mastered using the rear, even then it's much more effective to use the rear.
With this technique you should be able to perform full lock turns with the wheels barely turning, even momentarily stopping them if you want to get cockey
... slip the clutch, drag the back brake ... and a tip I learnt from an instructor of mine:
, and you're right, the heavy boxer twins aren't an easy bike to manhandle at slow speed. Pans and FJ's were a doddle compared to these!! 


It was too late and dark to turn around and try it from the other direction.
.On reflection I think all the roadworks have also had an effect on my lack of confidence .But I must admit I'm really getting back into riding my 1150gs just changed oil and filter in the morning I'll do gearbox and rear driveshaft oils.