Great question @Gatorsfn28,
Our system can easily maintain a canopy density of about a foot or 12 inches, so I like to remove all of the leaves that are in the dark, meaning at the bottom of the canopy. If the leaf isn’t getting enough light, remove it. It will start to die off and tell you it wants to go anyway.
Some growers are fans of extreme pruning, allowing the growth to return after taking down the majority of leaf, but I think it causes too much stress, I use a lighter hand removing leaves.
Hope that helps,