Panasonic GH5+Olympus 12-100mm f4.0+Camvate Camera Rig Cage+ Saramonic SmartRig+ Pre-Amp + Aputure Diety microphone + Audio Technica isolating headphones.
Manfrotto fluid head and Berlebach wooden tripod. Add batteries. Push red button. Make sure you see the flashing red indicator or nothing really happened.
Test it all before you go out the door.
Make sure you can look through your viewfinder without poking yourself in the eye with the back of the microphone.
Test the lens with the body you're going to use it with.
Have a plan to take the whole rig off the tripod.
Work with your pre-amp enough times that you know where the gain knob is without having to look.
Grab the correct release lever. Nothing worse that watching a camera slide off the rails.
Figure out how you're going to hold that puppy when you want to move around.
Do you really need an external monitor if you need to be very mobile (not with the GH5 at 30 fps).
Can you access all the menu items quickly?
Is your cage rock solid?
Did you set the headphone levels correctly? (Any alternate advice on the proper way to set headphone levels? Chime in please!).
Did you bring the right tripod or do you wish you could go up another foot?
Did you get the advance check?
Did the bank cash it for you?