This Instructable contains some helpful tips for trying to come up with a great idea to pursue in your film class. These steps and tips can also be adapted to fit other situations you may need to produce an idea for.
Step 1: Find Somewhere Productive to Work
It is very important to find somewhere where there are no distractions that will interrupt your thought process. There are a few places around your school that would work, but by far the best is the library. The library is dedicated to offer students a place to work, and they usually have a quiet atmosphere. Also your classroom may work if you are not surrounded by loud inconsiderate people, that respect and contribute to a productive workplace.
Step 2: Jot Some Ideas Down
When you start to get your ideas on paper remember to write everything down, no matter how stupid it is it could still be helpful and you don't want to forget it.
Step 3: Different Ways to Get You Ideas on Paper
There are many different ways of taking down your ideas or expanding on an idea you already have. You could use the typical form of the jot note list, or you could try something like a mind map.
Step 4: Use a Friend
When you have a couple pages of ideas, get together with a friend and see what they think about them, start to narrow down to the best idea.
Step 5: What Interests You?
You don't want to be stuck doing something that you will get tired of half way through. Pick something you can see yourself going to the end with.
Step 6: Whats Realistic?
Go through the remaining ideas and cross out any that are unrealistic in terms of how much time you have, are you going to have to spend money, is it overly complicated or intricate, etc. (In the case of a school film project, something that needs insane special effects probably isn't a good idea).
Step 7: Test the Water
At this point you should be down to 2 or 3 ideas, think of what the first scene of the idea will look like, where is it going to go, and will it make sense, will it be easy to finish.
Step 8: Pick Your Idea and Go With It
Pick the idea that will work the best and stick with it.