Even though storyboarding isn't necessarily a required step in the filmmaking process, most filmmakers find it helpful in not only planning out their shots but seeing their stories come to life visually. Having a template that helps you do both of those things requires space to both sketch out your shots (or in my case, doodle like a 3-year-old) and jot down the necessary information, including shot size, shot type, and lens data.
The BuffNerd himself, filmmaker Jakob Owens and his team over at Tropic Colour have come out with some really handy, detailed storyboard templates that offer all of that and more.
When I first started storyboarding, there was no way I'd spend money on something I could draw up myself on a piece of paper. ("What, I can't draw a bunch of boxes and lines myself?")
But that task got really old really fast, so I went online and downloaded some free temples. But those were a little too simple and left a lot to be desired.