That kind of depends on the kind of film you want to make. If you want to make a comedic film, make an "incomplete" ending. That means the main conflict is about to be resolved, but the viewer can easily imagine what the ending will be. It could also mean that the main conflict is over, but a new conflict related to the main one comes up. Beware, don't be too abrupt in your ending. It sounds like your problem is your conclusion is missing. After a climax, you need to have a calmer moment before you end it.

develop the Characters.

Well, this is a difficult topic to really explain. Start with a style. Not some animation technique, but a common element in your films, such as a time period, or a universal theme, such as family, or revenge. and Alpha is right, develop characters. Nobody wants to see another generic main character. give him a tendency to do something, like jumping to conclusions, or making accusations, give him words he uses too much, give him personality. Do this with every character, the more personalities, the better. Write character sketches. Then, come up with a situation that requires multiple actions, and an actual problem. Like a social experiment gone wrong, or a powerful empire arising out of nowhere, or an apocalyptic disaster and the struggle to survive. Now take your characters and throw them into the situation and spend about a day deciding how they will react and the consequences. as long as the problem is resolved in the end, you have a story. And as long as it isn't generic or dull, it's probably a good one too.

Wow Realbrick, your post has inspired me in writing my scripts. I've never really developed my characters, and you explained how to do it awesomely. Thanks!

I would say so, the characters have their own personalities and motives in the story. Perhaps you should also consider other ways of expressing personalities. Even the car a character drives can help with that (personal taste is very influential.) for example, a person who drives this:

would have a different taste than a person who drives this:

And you can also hide things about a character, but let the audience make the assumption. For example, a salesmen type person wouldn't say "I want your money." but the dialog could be slowly inferring that. That's a really bad example, but I cannot come up with one at the moment.

Although this gets focused on often too much, I think that an important part of a story is a strong climax. One of the reasons that people did not seem to love the story in "Egyptian Holiday" (no offense mobile, I loved the film ) was because the climax was short and not too suspenseful. Even in a comedy, it is possible to achieve a strong climax. Remember, the entire film is building up to the climax, so it should be the most important part of the story in my opinion.