There are many systems in use to provide safety whilst working.
These can be: not allowing lone working (rather difficult for one man bands), permit to work systems, method statements risk assessments etc.
At the end of the day, you are responsible for your own and anyone else's safety that your actions could affect.
As such it is your duty to ensure that danger to yourself and others is minimised, this can be achieved by implementing a safe sytem of work.
The exact nature of the system is up to you to determine, preferably to my mind, something which will become second nature.
A bit like allways glancing over your shoulder before making a turn or overtaking.