Are you unintentionally shooting against white walls? Are you not checking white balance? Are you casting a buddy from your dorm to play a police chief? These are common mistakes beginning filmmakers make, and it's really helpful to be reminded of them. However, they are just symptoms of a larger problem, which is why this video from The Basic Filmmaker is so important for beginners, pros, and everyone in between
The main point that the Basic Filmmaker is trying to get across is that, yeah, beginner filmmakers make a lot of mistakes, and that's okay, but if they continue to make mistakes it's probably because they're not behind the camera (or writing or editing) enough. You're not drilling yourself -- you're not doing it!
Imagine your filmmaking is your body, and the mistakes you make are ailments. You've got a sore throat, so you pop some lozenges. You've got a headache, so you take some pain killers. Upset stomach? Drink some flat 7-Up. You can combat each of these symptoms with some sort of remedy, however, it won't cure your sickness and it surely won't prevent you from getting sick in the future. What you need is to diagnose the actual problem, that way you don't waste your time trying to cure the symptoms.
Practicing making films (which is just making films), is a great preventative for making silly mistakes. Of course, this doesn't mean that you'll never make them again, but it'll help you commit things to muscle memory. Eventually, you won't have to think too much about avoiding shooting against boring white walls or checking your white balance, because it's just something you always do.
Source: The Basic Filmmaker