There is so much great info here. When people ask about these things I figure they don't waqnt to read and in this day of video everything - to You Tube with them for demo. Then they get interested and research more. Hopefully. Good link. I top, then fim the tops of those branches.
Topping completely removing the upper most growth node. Result the growth hormone shoots down the lower portion of the plant. Decreases vertical growth and makes lower growth try to catch up to your new top point.
Fimming ( Fuck I Missed) it is like topping however you leave about 10% of the newest growth. Result shoots growth hormone down but not all the way. The growth hormone lingers at the point you fimmed. It divides your central cola into more smaller colas.