Don’t use the motor switch off command while the drone is in the air (combination stick command – when you pull both joysticks inwards) . It will turn off the motors and your drone will go down. Even when you have landed the drone don’t use that command either. It’s way too easy to do it incorrectly tipping over the drone (happened to me). Just hold the throttle down for 3 seconds.
Use propeller guards. If your drone happens to hit a wall or a tree without the propeller guards one of the the propellers will most likely break off, that will definitely make the drone uncontrollable and it will end up on the ground. With the guards the most likely scenario is that the drone will simply bump into the obstacle without breaking the props and will carry on flying.
Don’t fly stupidly low. I’ve seen videos of people flying their drone 1 metre off the ground (3 ft). You are just asking for trouble. Any mistake and your precious drone will hit the ground and somersault most probably damaging the propellers. But the damage could be more serious depending on the speed and the surface it’s flying over. (Water = total loss, grass = damaged props, asphalt = possible damage to the camera)
Don’t fly when it’s windy. Even though the drone is extremely good at battling wind there is a limit to everything. Also the higher you fly the higher the wind will probably be. And I’m not aware of any app that takes wind into account when calculating the time remaining (DJI GO or Litchi). So while you might be able to fly away the drone might not be able to return due to high wind.
Set the return to home home altitude to 100 metres (330 ft) to make absolutely sure when it comes back it won’t hit anything. Don’t rely on the drone landing itself, unless you’re on a field, return to home function is notorious for being quite inaccurate, the drone could end up landing itself up to 10 metres away from the point it took off. As soon as you can see the drone, take over and land it manually.
When you take off let the drone hover at low altitude for about 30 seconds. This will give you a chance to notice any potential issues with the drone (such as a battery malfunction).
Fly in GPS mode and avoid ATTI mode, especially in an area with a lot of obstacles.