New guy question

ok here is a question from the new guy
My girls are very thick with foliage.
I am week of 3 of 12 /12 .
How much can I trim without hurting them.
Thanks
The Conch

As far as numbers go I have heard 1/3 but I generally keep up on it throughout so I don't have to do a major attact.

But it never works and I end up trimming a good bunch from the bottom at about three weeks flower

Knock yourself out.
Unless it is a super finicky variety and you use common sense you will be ok