Thrusters

Stand with your feet in a squat stance, holding a barbell in the front rack position (resting on your shoulders, with elbows high).
Keeping your chest up and core braced, descend into a full squat, aiming for your hips to go below your knees.
From the bottom of the squat, explode upwards. Use the powerful momentum from your legs and hips to press the barbell overhead in one fluid motion until your arms are fully locked out.
Lower the bar with control back to the starting rack position to complete the rep.

Tips

Keep your elbows high and pointing forward throughout the squat so the bar stays balanced on your shoulders rather than rolling onto your wrists.
Time the press so the bar leaves your shoulders just as your legs reach full extension, letting the upward drive from your hips carry the bar into the overhead lockout.
Lower the bar back to the front rack position with control before beginning the next squat, rather than dropping it abruptly onto your shoulders.

Pressing the bar before reaching the bottom of the squat, turning the movement into two separate exercises instead of one continuous thruster.
Letting the elbows drop during the squat, which causes the bar to shift forward off the shoulders and makes it harder to transfer leg drive into the press.
Cutting the squat short so the hips do not descend below the knees, leaving the overhead press to be completed by the arms alone without the leg drive the movement relies on.