It appears I break all the rules stated so far with chisels bit like telling a world class cricketer how to handle a bat. There is a right way to do everything however I never rely on the size of the bushes using them as spacers and a quick guide.
Might I say turning Palm Tree blanks and soft timber blanks soon teach the need for different techniques all explained above.
Treat the bushes well the results will improve. One thing I find helps I cut using scissors my sanding sheets into 1/2 inch strips giving me better control when sanding.
Peter.