Begin with your abs tight and your ribs pulled down. Think of using your abs to control the space between your ribs and the front of your pelvis, and don’t let them get further apart as you move, while keeping your shoulders back.
Press one weight overhead and keep the other at your side.
Carry the weights with tightly braced abs while keeping your shoulders back and your head neutral.
Don’t slouch or let the weight pull you to the side.