Here is a quick and useful tip that you might already know. Let’s say you are drawing a shape in After Effects.
Then you close your shape.
But then you are like, oh man I did not mean to close it. So the big question is now how do I open it back up?
You can continue to drag on it but that is not going to do it. So what you need to do is to select 2 points that you want to open.
Right-click and go to Mask and Shape Path and make sure you click on Closed.
When you click on Closed, it is going to open the shape back up.
Select the point that you want to keep drawing with.
Now you can continue adding more points with the Pen tool and then connect it again.