Using bands as a form of accommodating resistance is tough. It requires stabilization, motor control, and oftentimes greater levels of strength because the amount of tension increases near lockout as the bands stretch out.
Be prepared to tighten up every muscle in your body when you do these, especially at the top and during the eccentric or lifting phase. And if you do these right, the bands will feel like a slingshot trying to launch the bar back into your body. This produces a strong deceleration force and triggers a significant neuromuscular potentiation effect.
You can do these standing or kneeling. The kneeling variation is a great option for lifters that aren't strong enough to use bands that are being fully stretched in the overhead standing position.