I am a subscriber of this YT channel Drone Valley. This post is geared more towards beginners, novices. The items listed above should be a part of your preflight check list and / or preventative, routine maintenance and inspections (blades and batteries).
Note: I do not agree with everything said in this video besides the main points of inspecting and maintaining your batteries and propeller blades, and also scouting the location (boundries) before flight.