Although you need to find a method that works for you, however I do the following:
I do the paper, without using notes.
I then will mark the paper using the mark scheme.
Then I use the mark scheme and my notes to make sure I understand any marks that I was not 100% confident that I gained.
Finally, I read the examiners report, and also find out the UMS marks I would have gained on that paper, to make sure I'm on track.