If you're like many people, you think of heavy weights when you think of performing proper squats, though the added weights are not always necessary and it will be much easier to learn proper form without weights. To start doing proper squats, make sure you are dressed correctly for the activity. Clothing should not restrict your movement in any way, and your shoes should be well cushioned and comfortable. If you regularly wear any braces or doctor-prescribed orthotics, be sure to wear these during the exercise and use them properly.
Correct body position is the most important element of all proper squats. Your feet should be spread a little more than hip width apart for stability. Your body weight should be rested on the balls of the feet to encourage good balance throughout the squat movement, and your shoulders should be straight and relaxed. When performing proper squats, it is important to keep your back straight; many people make the mistake of arching the back or otherwise bending it during the squatting motion, which can cause you to lose your balance. It can also lead to excess strain on the muscles of the back and shoulders, which is counterproductive to the exercise's intent.
When lowering the upper body, you will need to bend at the knees until you reach about a 90-degree angle. Your hips should never drop below the plane of your thighs, which means your thighs should never be horizontal during the squatting motion. Proper squats dictate that you bend slightly at the hips as well, but not so much that your upper body thrusts forward. To encourage better balance and to keep your back in the proper position, you should extend your arms forward away from the body as you lower your body during the squat.
When you reach the lowest point in the proper squats, you should hold this position momentarily before returning to the starting position. This will give you the most strength building benefit and will ensure you are properly balanced before beginning the return motion. When you do return to the starting position, do so slowly and deliberately. The return motion will give you just as much benefit as the squatting motion. Rest only for a moment between repetitions, and then rest for a longer period of time between sets. Do not try to do too much all at once, as this can be too stressful for your muscles, potentially leading to injury.