I go back and forth on topping. I always used to top. One plant I topped seven times. That is 128 main tops. But now most of my strains flower too early to do much topping. Plus I have lost several over the years to splitting. If you do top, make sure you use tape or wire to support the Y.
Now I LOB {Lean over Baby} more. When the plant gets 18-24 inches, stake it down as low as possible. Keep staking down the main tip as it grows. If space allows, you can stake down the side branches too. When flowering starts for real, I turn them all loose so there will be some give to the plant. I've had several break when heavy with bud where it was staked down.