To ensure your sit-stand desk is set up correctly, start by adjusting the height of the desk so that your elbows are at a 90-degree angle when typing. Make sure your monitor is at eye level and an arm's length away from you. Stand with your feet flat on the ground and ensure that the desk is stable and doesn't wobble. Take frequent breaks and change positions often to avoid strain. Experiment with different standing and sitting positions to find what works best for you.