How's your slurred string crossing technique? We've just added the first video tutorial to course 1D, and it's a smooooth ride for those that string-cross steadily...

Or, if you're still getting to grips with music theory, then Setareh has a 'Quick Fix' for your sixteenth notes (or as we like to call them here in Britain, semiquavers...!), over in the Beginner Quick Start course:

Enjoy!