Another tip, really get a feel for how an entire car can be in your blind spot, roughly just behind you on the left and right. That is part of the reason for watching your mirrors ~15-20% of the time.
Adjust your mirrors to eliminate the blind spots as much as you can. Not perfect, as modern A-pillars are enormous and severely hurt driver visibility, but you will have much better situational awareness.
Sample description with video: https://glassdoctor.com/blog/adjust-your-car-mirrors-for-max...