I have different methods of topping but I will cover my 2 main methods any others would be a variation of these 2, The 2 are topping and removing all but 2 nodes or topping but leave everything on. I will start by describing the latter and I am putting this just for my journal in general, if using my remove all method I top 3 times usually.
Topping but leave everything
So for this method I will decide how many colas I want to try get at the canopy in flower, keeping in mind if the stalk is symmetric you get 2 colas per node, and when I am happy I will top the plant above my last desired node. I will now give them some time to bounce back but next I take the very top node and I bend them out stopping them from growing up and keep doing this until each lower set of growth catches up to the top.
Advantages are it is the faster method
Disadvantage are that it isn't the symmetrical method and some colas always try grow faster or bigger
Topping and removing all
So for this method I watch all the node growths till I find one where both sides are growing at same speed and the same size where I feel it will best stay symmetrical throughout its growth, try pick a low down node but not the first or maybe not the second one. When I decide on a node to keep I will wait until I see just enough growth from that nodes crotches that I know the node is formed enough to play with, when I have about 1/2 cm of growth or I first see a little stem I will top above that node. The difference in this method is that I now remove every lower node other then the very top one and grow out only 2 shoots from the 1 node, now I go back to looking for the most symmetrical nodes but now I also look at both together in terms of distance from center. After smoking a nice doobie I can usually make my mind up on what node I want to keep on both sides and wait for that node to be ready, this means waiting for that crotch to send out some growth then snip. If done successfully every time you do this topping you will double your colas so now you top until you have the number of colas you want.
Advantages are it is symmetrical and pretty plus it is easier to get the plant to grow flat while training it
Disadvantages are that sometimes the plant gets stressed and slows or just the method is already slower as you are removing it's main shoot so many times potentially