Hello C ,It's quite difficult to explain without a decent pic...........

At the very top of you're plant there is the very freshest new growth just bellow the new growth were it joins the main stem thats were you cut it off.
However make sure that the cut is above the diagonal shoots growing from the node bellow
With the main stem cut off all additional growing will come from the two shoots bellow the cut, making two main stems to produce buds.

I've grown with and without pinching (topping) and have found that by having two main budding stems that it does increase the yeild quite a bit


I suppose that it could be used for keeping a plant low, I've never used it for that reason, check this thread out C .............................

http://boards.cannabis.com/showthread.php?t=18629



Love mand xxx