It's amazing how much abuse the plant can take and keep on growing. Of course you want as many tops as you can get, but the single best training you can do to get bigger tops? Thin out all that larfy crap that isn't gettting any light, the plant will direct more energy to whats left in prime light. I tend to leave the leaves and take the growing shoots/tops/branches that won't ever finish or it won't be worth it to go that long anyway. Mind you total yield might actually go down, but it's worth it to me to not deal with all the bullshit tiny premature nugs anyway. This a correlation between bigger stems and bigger buds, but only where there is bigger light.