Pen Tool is an essential tool in Adobe Illustrator. This allows you to define your anchor points and adjust the curves associated with that anchor, using only two control points associated with each anchor.
Adobe Illustrator Pen tool Keyboard shortcuts
Select Pen Tool (P)
Select Add Anchor Point Tool (+)
Select Delete Anchor Point Tool (-)
Select Convert Anchor Point Tool (Shift-C)
Select Scissors Tool (C)
Join two anchor points (Command/Control-J)