When to top

If planning to top your plants, when should you do so? I have read that some top based on size in inches, and other top based on number of leaf sets? So I am looking for some more opinions as to when is the proper time to top a plant? Also is it possible to top a plant too early and screw the thing up?

leaf set mate is the way i'd go but after its got 4 sets you can do it anytime, btw some plants DONT like it.

Have a look at this thread - the first post will probably help you greatly.

https://www.rollitup.org/advanced-marijuana-cultivation/151706-uncle-bens-topping-technique-get-111.html

thats where i learned

I also top at the 4th set and have for all but my first grow and it has worked very well for me.