Safety is worth it.
Always fly within a predetermined area, with a spotter making sure that no one comes within a 30m radius of that area. If they do, land immediately, away from the person. Ensure that no high velocity flight path is in a direction that could lead to a crash 30m outside of the predetermined area.
Never arm a quad within 10m of people
If the propellers are mounted incorrectly, or the drone is incorrectly configured, it can jump up from the ground uncontrollably in random unpredictable directions. Never arm a quad within 10m of a person.
Always follow battery safety instructions
Many hobbyists and pros alike have literally and tragically had their houses burned down and in some cases lost all their belongings due to a battery fire. Follow all safety instructions and never leave charging batteries unattended.
Don’t take risks
Be realistic about your skill level and don't take risks beyond what you know you can do. If you can follow that simple rule then you will be a much safer pilot. It will also make it more likely that you will keep your gear in good condition for a long time.
Know your limits
Every country has different laws, you should follow them. It makes sense to not fly near other aircraft, staying low is a good idea.
Be calculated and careful
Successful and safe flying is about having a flight plan that you create in your mind and then follow. This allows you to make predictive inputs rather than reactive responses. It's reactive responses that lead to mistakes, stay one step ahead at all times.