The favourites bar allows you to directly access up to 5 functions – regardless of which menu you are currently in – and thus use shortcuts. You can find the customisable option under "Settings > System > Favourites bar". There you can set up various shortcuts, including "Skip waypoint", "Screen shot", "Next track", "Play / pause" or "End call".
To jump to the favourites bar while riding, press and hold the multicontroller to the right.