The basis of any squat is great form. The following tips will help you perfect your form:
Face forward with your feet shoulder-width apart.
Place your hands on your hips or stretch them out in front of you for balance.
Bending at the knees, lower yourself as if you're about to sit in an imaginary chair, being mindful not to round your back or lean your chest onto your thighs.
The aim is to get your thighs as parallel to the floor as possible.
Push back into starting position, driving your weight into your heels.