Watch: How I Sketch - An Intro
The Interactive Sketching Notation is a visual language which enables designers to tell more powerful stories of interaction. Through a few simple rules, what the user sees (drawn in greyscale) and does (drawn in red) are unified into a coherent sketching system. Intended for Adobe Illustrator, but friendly towards Photoshop & Balsamiq.
Having merged flows, user stories, sketches and wireframes into one document, it is easier to maintain your work with the notation.
The notation has clear start and end paths showing user actions explicitly in red. Don't just show the UI, but tell a story.
The notation helps you cut corners as much as possible with the benefit of speed. Don't worry about too much detail in the beginning.
The notation relies on large workspaces with room for multiple A/B/C ideas. Don't get locked into the first idea that comes to mind.
The template gets better with time like a fine wine. Buy it now and get free lifetime updates.
Use it on commercial projects of course in whatever shape or form.