You can practice proper squatting form, and/or do some stretching.

Practice makes perfect, so if you want to get better at going ATG on your squats, start by doing so with just your body weight, then use light weights as you feel more comfortable.

DYNAMIC STRETCHING will be particularly useful for improving your SQUAT. The more you can loosen up your hips (think hip flexor stretches) the better. Ankle mobility is also key.

Remember some people will be naturally more flexible than others, but just like weight training, you will get better at it the more you do it.

Check out the video below for more details!

Maximize Your Squat For More STRENGTH, FLEXIBILITY, BALANCE & OVERALL POWER!

Related Questions:

1. Is it bad to go past 90 degrees on my squat?
2. What are static stretches and dynamic stretches and which is best?