It was hard if you were impatient.
Easiest maps were with the Spy and Diver.
It was like playing chess.
Watch the pieces, identify which outlying ones can be taken out first without raising suspicion, rinse and repeat.
I used to like trying different ways of doing things. Killing someone and leaving them to be found but I'd placed mines near them etc

really makes you appreciate how fun it must have been to make.