I hate storyboarding. Let's just get that out there straight away. Although I can draw to an extent, I find the whole process tedious and a drag. Being somebody that hates it so much, I think I can tell you that my short films have got better since I started storyboarding.
If you can't draw and will never attempt it, then do what my friend does - write an excruciatingly detailed shot list. Describe your shots with words. I prefer to storyboard because I am more visual and I find it quicker. Whatever your choice I really would suggest that you do this before you start shooting.
Here's a few reasons why:
1. Storyboarding, first and foremost, makes shooting easier for YOU: Alfred Hitchcock is famously known for saying that the actual filming part of his filmmaking process bored him. This was because he planned his shots so meticulously beforehand that the shooting part was just routine. It was necessary but not creative. All the creativity had happened before. The more detailed and stronger the storyboard, the less stress and panic you have to put into the actual shooting.
Imagine: On set, suddenly, the director becomes the person to talk to. I am quite an introvert, I hide in the corner at social events. So imagine my shock and horror the first few times I directed my short films, to realise that suddenly EVERYBODY wanted to talk to me. And what's worse - they want to ask me questions and then make decisions! Technical problems arise, actors want feedback from you, DoPs think they have full rights on your attentions - all you want to do is get your performances and shots. Try and imagine all that hassle around you while you are trying to make up shots as you go. It means you're focus is drastically impaired. With a detailed storyboard all you have to do is look at what your shots should be and follow them to the letter. Then you can answers the questions being shot at you without ruining your production.
2. Storyboarding allows you to see the rubbish: It's amazing how every single time I am storyboarding a new short film, I realise that some lines or some shots don't need to be there. I don't understand the science of it, but somehow, writing a story in your head seems to mean you add bits that don't add to or explain the story. Drawing the scenes out, shot by shot, means that you are essentially reading your own film as a comic book -and that's when you realise the areas that don't make sense. Storyboarding also lets you know how strong your story is.
3. Storyboarding helps you plan better: I am sketching away when suddenly I think, "Oh - I need to have that prop ready!" When you are making short films with a minuscule crew and you are doing most of the jobs it is so easy to forget things. Props, especially very simple essential props you might know you would have to hand are top of the list of things you might forget. Storyboarding, actually drawing the necessary props seems to implant them in your mind more than if they were written down in a list. Of course, I am sure for some people, writing it down will be more helpful
4. Storyboarding enlightens: Shading in your sketches allows you to think more clearly about what type of lighting you want and then what lights you will be using and how many. It also enables you to think about the setup time between shots where lights may need to be moved for a wider shot. That in turn may help you with your scheduling.
Anyway, enough from me, the amateur. Listen to some pros: