How many shots do you take to get a shot?

Out the other day with zillions of tourists in Sydney and saw everything from smartphones, iPads, compacts, M4/3 and mirrorless others, consumer DSLRs and some humungous DSLRs being used to record things happening around Sydney Harbour.

I couldn't help noticing that the humungous DSLR users often seemed to take a burst of 4 or 5 shots for every single scene that they took. So the question, what do you do?

I fall into the "usually one shot but sometimes take a couple or more if important or possibly shaky" group. Habit follows from film days where every shutter press cost something.

Thanks and regards.... Guy