Writing reviews of novels

I received an email from Mack Lundy of Mack Captures Crime (previously Mack Pitches Up), which asks the questions:

On average, how long does it take you to write a book review of a novel? Do you take notes as you read? Again for a novel.

I thought I would share the answer that I sent him:

I draft a review in an hour or so, but I go back to it about five more times to read through, edit etc before sending it off or posting it- sometimes I change substantially or add things. Sometimes I take notes or bookmark pages, sometimes I just write general impression at the end. If I come across things in the book that I especially like I bookmark or note them. I don't have any general rule, though – sometimes I have a strong impression from a book while I am reading it and it is very clear to me what I think, so I won't take notes. Other times I am less sure so I do – but not to the extent that it spoils "the reading experience".