In the old days this was done by practise and experience but now we have become lazy and reliant on the technology working as advertised.
Just a small point and you may well be aware of it anyway;
We haven't become lazy, we have become complacent. It seems like a pedantic point but it is very important because one is caused by a poor attitude and could be resolved at the recruitment stage, and the other is caused by evolutionary heuristics which need to be understood to solve the problem. When that small (large) point of difference became clear to me it completely changed how I viewed the problems the industry faces around maintaining pilot skills so I thought it worth mentioning as it may do the same for others.
Cheers