Before brainstorming your idea, you’ll need to consider your own Flash skill set when it comes to the movie you want to make. If you’re too ambitious with what you want to create, the project might overwhelm you, and you might abandon it. Also, consider time constraints. How many characters and backgrounds can you realistically draw? If this is your first film, you might want to consider setting your scenes in one or two different backgrounds and limiting the number of characters you introduce to your audience.
To get a feel for what’s popular and what works in Flash, visit a Web site such as NewGrounds.com, where users vote on Flash animations that are uploaded daily by independent animators. NewGrounds.com will give you an idea of what viewers enjoy when it comes to Flash movies through its rating system. Browsing the site might even spark some story or character ideas. Though, don’t let what’s currently popular limit your creativity.
If you want to base a short film off of a current Internet fad or hot topic, browse social news sites such as Reddit.com and Digg.com for what people are talking about. Your movie might have more viral potential this way. In other words, people might share the video with friends and family because it’s relevant to them.
If you’re not interested in current fads, rely on your own imagination. Usually, it’s a good idea to go with what you know--keep a notepad with you during your day and write down anything interesting that happens. Review it later, and you might come up with some material.
You’ll want to condense a beginning, a middle, and an end into a movie that will only be about a minute or two long. For ideas on how a short storyline should work, check out the comics in your Sunday paper, watch short films, or read flash fiction (a term for incredibly short stories that are usually the length of a paragraph). Going through all these different story forms might spark some more ideas as well.
Once you familiarize yourself with how a short story works, remember to write out your story before you animate it. Plan ahead, and your movie will be more coherent and structured.