How often your task estimates end up being accurate?View other answers to this thread
At work, I'd say most of the time, however we use Scrum, so we don't estimate time; we estimate complexity. We have a rough story with a given number of points and we compare the task to be estimated against it. We get a consensus using planning poker, and that's usually pretty spot on.
At home, for my private customers, I do have to estimate time, and I'd say I am right quiet often. I split up my tasks into small tasks for which it is easy to estimate how long it will take to implement them. Then I add them up and double the total. That's what I tell my customer. I usually finish way ahead (remember: I doubled the time), however the extra time lets me work on things in parallel or be spontaneous about how I spend my time.
Mihai Deta Planning Poker is the name of an agile/scrum technique. Roughly, you present a ticket to the team, and everyone gives their own numerical estimation of the complexity at the same time without talking about it. You can read more about it on Wikipedia.