Main lining is a long training: you top your plant, leaving one node, wait for the branches to grow few nodes, cut again, and again, and again…
For every varieties I grow, I like to do only one topping (nodes 2 & 3) and I keep the removed part as cutting (so I can grow exactly the same plant several times if I really like it). The plant grow fairly quick, with 4 main colas and several latterals branches. ^^