@xahteiwi I've gone with C), but it also depends on how well-structured the topic already is in my mind, and whether I'm talking to an expert audience or conveying complex topics to one that's new to them, or whether it required active research.
I've had successful talks that I wrote in a day, and some I was only happy enough with in the third or fourth iteration at the very least.

@larsmb I think C or D are both good options. I consider a factor of >30 to be reasonable, over 60 happens too. The problem is that a lot of people who know nothing about speaking, or think they do good talks when honestly they really don't, think it's about 10.

@xahteiwi @larsmb I chose option B and would guess that most times I am satisfied are close to 30. However, there are some that surprised me where I definitely did not have to spend more than 10 and was happy. My most intense one (a keynote) was last year and I think I was getting close to 60 but did not exceed it. The additional effort was mostly in basically preparing it twice, presenting it first at a smaller event, doing 3 serious internal test runs and …