The Superman Press, a.k.a. Prone Press, can be performed with bodyweight, or with light plates, or with light dumbbells.
START: Lay flat on the ground and pin your shoulders back, pushing your chest out.
FINISH: Perform a shoulder press motion. The further your hands get from your body, the harder you’ll need to work to keep posture (possible weakness in your rear delts and/or lower traps).
TIP: To increase difficulty, lift your feet off the ground to introduce less stability and a static hamstring hold.