This is going to sound odd but many times I base my on whom I think I may be working with.
If there is a certain cinematographer who gets really excited about difficult shots or “outside the box” framing, I may write a short with a dramatic or romantic turn. I will typically start with a set-piece in mind and build the story around a single scene idea. If my idea seems creepy, I’ll approach a DP who is almost preoccupied with horror films. Either way I’ll bounce the set piece concept off the DP and we will brainstorm where the idea can grow. Now this is KEY. The DP usually knows people with whom they prefer to work. Go with it!
The cinematographer usually knows who they can trust and communicate with so that things run smoothly. Lights, camera, audio, electrician, grip are usually team members its best for the DP to hire. As the director you need an assistant director and a script supervisor. On small projects the same person can fill both positions. What’s next? Oh yeah, casting!
Well since every filmmaker knows at least a dozen people who want to be actors you would think it wouldn’t be a problem. I encourage you, however, to have each of those interested actors send you a self-taped read using a few lines from your script. Additionally, take advantage of social media and put out a casting call. I mean, why not? You may strike gold. And with an audition you can make sure that the right people are playing the right characters. You can’t go wrong asking for a one-minute self-tape.