you can do many things to make you plant yeild more, and topping is one of them. during your first 3-5 weeks of growth your plant will produce nothing but twin fan leaves. thats one on each side of the stem at the exact same level. then the limbs or branches will come out of the space btween the fan leaves and the stem, one on each side. more or less twin branches at the exact same level from the fan leaves. the fan leaves are not the branches, the branches will come out like a new shoot from btween the fan leaf and the stem, just like the new shoot on the top, when these twin branches are more than 3 nodes it is safe to take them for clones. to top your plant just snip the new shoot btween the new branches on the top when you notice them coming from the fan leaves at the top. DONT snip the branches just the new shoot