Keep the weight close to your body. Pull your shoulder blades down your back to help with this. Imagine squeezing a clutch purse between your upper arm and armpit.
Keep your back straight.
Keep your knees stacked directly over your ankles.
Press your feet strongly into the ground.
Feel your hamstrings. Imagine you are going to kick your butt with your heels. This can help you find your hamstrings.