What I've Learnt
Be organised and make sure everything for your shoot is planned. Be over pre-pared for any situation that could occur, whether its an actor that dropped out, the weather isn't on your side or your location fell through last minute. Over-plan and always have a back-up.
Make sure you have all items needed for your shoot. Sometimes one thing missing can make such a big different especially with set-design. Think, Plan and retrieve what you need or make it. It will all be worth the effort when you see the end result.
I felt I had learnt a lot from the level 6 shoots I have worked on. Its not only about who I work with but the decisions behind who's in my film. People always say just deal with them, but sometimes this can be the downfall of your film. Sometimes opposing ideas or beliefs on a subject can cause friction and add an environment around the shoot. So i've learnt to pick wisely with my own crew to ensure everyone can get on and bounce off of each other.