Hold down on the pen tool icon in the tool,bar and you will see a convert point tool. This tool is use to create curves from the corner points. Just drag on the selected point and it will create new handles. You can repeat this process as many times as you wish if needed. Clicking once on a point will make it a corner point again.
Short cut time on windows computer - you can hit the p key to select the pen tool. While you have the pen tool selected, you can use the modifier keys.
shift key - removes points
ctrl key - direct selection tool
alt key - convert points tool