(1) Seated Barbell Forearm Curls. Sit on bench and rest your forearms near the end of bench, then with your palms up, curl the bar with your forearms. You have the option of keeping your hands tight around the bar and curling at your wrists only, OR when you get to the low part you can let the bar roll down into your fingers, then roll it back up with your fingers and finish curling with your hands around the bar. So you can curl by bending just at your wrists, or bend at your wrists, then your fingers.
(2) Seated Barbell Forearm Extension. Same exercise but with palms down. You can't use your fingers though.
(3) Standing behind back barbell forearm curl. As in (1), you can curl at your wrists or both your wrists and fingers.
I like supersetting (1) with (2). I also think that, with the curling movements, it is a good idea to curl at your wrists and fingers until your fingers fail, and then just curl with you wrists alone until your wrists fail.