When you are going to cut a fan leaf off it should be during the veg. stage. In my experiance, I wait till I see leaves forming at the base of the fan leaf. That is where a bud could form. I have a logic to it, If the fan leaf is at least 4 inches from the top/cola, I know that once those leaves start to form it has it's own sorce to grow/feed from. The way that it works out for me is, for every fan/sun leaf that I cut off, I have a new cola starting to form, and once the leave is cut off (from the base) it will start to stretch and grow on its own. To be a nice cola with time, or a good sized clone to continue the saga. . .I wish I had a pic. to show what I mean. . .