Actions are the business tbh and this is a good introduction to using them.
I use several self created actions for little things like say I created a vector path between 2-3 points, I use upto 3 actions to decide what to do with it - Stroke: With Pressure Sim., Stroke Without Pressure Sim & Stroke Fill, so it inks the line/space I created- it also deletes the path as well.
Another one I use is for Block fills - It selects the Bucket tool, Expands the selection by 2 Pixels, Fills the selected area and then Deselects - combine with the Quick Selection/Magic Wand tool this is a great time saver. I have one the contracts the selection too for Masking.
Its the little things that make a difference