These can be achieved by creating different layers in AE that can follow the sequence of an ink type of thing, once all the layer in your composition just go to the Animation menu and select under Keyframe Assistant - Sequence Layers.
I used to do it for creating film scratches and hairs, so i will get an Illustrator path and apply different type of strokes.
A lot of the things you will see in packages like D Juice are looks you can make on your own. The main thing to me, is simply the time saving aspect of them. If your a busy animator their great. If you have the time, it's fun to challenge yourself and create your own.