Cropping, 12/12?

So im getting ready to go to 12/12, I have my nutrients ready. My friend told me I should crop the top so they grow "bushy", should I and how? Anything else I should do when i switch to 12/12?

if you`re gonna top themleave them in veg.don`t flower until they heal
stress might affect sex

Yea. FIM is the best topping technique in my opinion, but this is to be done in veg and stopped a month prior to flowering for the plant to heal and grow some new mass.

You can LST safely in flower. I did it with my last outdoor grow and it really helped.

I also FIMed a few buds a couple of weeks into flowering to see if it would split and grow 2 buds, and it did. It took about a week or so to heal, but when it did, it split into 4 buds. They were a bit smaller than what the original bud would have been, but im guessing i got an extra 75% off that bud.

Watch out for mold at the wound site if you FIM during flower.