I am sure anyone who is familiar with filmmaking understands it well, but I guess it might be interesting to share some of the problems I have encountered before when I was making films:
Solution: We tried our best to persuade him, but failed. So we stopped filming for a month and rewrote the scrīpt.
Lesson: Prepare a contract, (actor's release), especially for actors whom you don't know well.
Solution: We tried our best to persuade him, and luckily it worked.
Lesson: Try to understand everyone working with you, learn about them more before you actually work with them. And certainly be considerate and try to make the best arrangement for everyone.
Solution: Since we couldn't afford another shooting day, we just had to fix it during post-production, which worked, but not very well.
Lesson: Try not to plan too tight.
Solution: Talk, talk, talk...
Lesson: Discussion is important, plus it is also good to also keep your stuff in written form. It helps for everyone to understand what you think and keep track.
Solution: Cut them all out, that's why there is something called "deleted scene".
Lesson: If something really don't fit, just forget mercy, forget how hard you have tried to shoot such scenes, simply throw them away. It is always better to discard earlier than later. Don't feel like you waste everyone's effort, coz it is just the opposite, if you keep the misfit, you are actually wasting their efforts.
There are still a lot more I wanna write, but I guess that's it for now, and we'll try again some other time...
Don't forget your dream!