Planning and Communication.
One cannot exist without the other, when it comes to making a film. You have a crew. This is great! You have people that are paid either cash or pizza to listen to your ideas. You are asking them to share their skills! Yay, everyone is contributing!! But this does not and will not work without good, no, great communication.
I don't mean a text here and there, or an email once in a blue to make sure everyone is actively still working on the same project. I mean a real play by play (if you're hands on and involved, as I am) the good the bad, the worst, the better. It's just great to know how every part of your project is functioning. Even the parts that don't directly involve you.
Email your cast and crew to check in. I am currently in a different state than most of our cast and crew. We use a lot of ways to stay in communication (thankfully there are a lot of options). From Google Hangouts to Facebook Messenger, email, social media, as well as texting and phone calls.
Because planning and communication are 70% of how your project will get off the ground, then it's important to make sure that you set the expectation ahead of time. Unexpected things are going to happen regardless. But if you plan to shoot on the lovely day before, you don't have to worry about that snow storm that came out of no where. All about planning, people.
Don't take short cuts and don't just ask everyone to show up. Plan things out and communicate efficiently with your peeps. Believe me, they'll not only appreciate it, but it shows professionalism and a standard that you set. Which makes you look good and makes the whole process that much better.