Bezier Tool

Action Result
Mouse
click (no selection) add a point
click (on selection) when its the last point of an open contour the contour will become the main contour to add points
click shift adds point which is on the x, y or 45° of the previous on curve point
drag adds bcp, they are all smooth
drag shift move the bcps of the last added point on x, y or 45°
drag alt un-smooth the bcp
drag alt command set anchor point to smooth and mirror the other bcp if there is one
click command start a new contour
move over starting point can close the contour
Key board
arrow keys move last added point by 1 unit
arrow keys shift move last added point by 10 units
arrow keys shift command move last added point by 100 units