For revealing text or shapes as if they are drawn, I use Paint (the effect in AE, not the amazing MS app).
Select your text layer and open it in the layer viewer by double clicking it.
Select the eraser tool and use your wacom to trace the shape.
Now the whole shape is erased.
When you open the effect in the timeline (twirl down paint; twirl 'eraser 1'; twirl stroke options) you see the start and end.
At the beginning of the animation put a keyframe for 'start' at 0%;
At the end of the animation, put a keyframe for 'start' at 100%
If you use an illustrator shape, with a little tweaking you can even copy the shape directly from illustrator and use it as the shape for the eraser.