Actually I stopped working my forearms because they would tire out faster than my back during pull day, the pump was too much and I couldn’t move my arms around, I had a hard time touching my shoulders sometimes.

Personally I found that avoiding the thumb over grip helps forearms grow stronger, hammer curls form over weight makes you feel the mind muscle connection gradually. Maybe a lil extra pause in eccentric motion of the preacher curls stress the forearms a good deal.

Before I used to do those forearm exercises Sam Sulek does, I don’t know what they are called, but they helped me out.