Let knees come forward. If you have access to a full length mirror at home, check your form from the side and aim to have you spine parallel to your shins. Feet should be shoulder width apart (Generally, but explore if wide makes you feel stronger and have better form. It depends heavily on how your femurs join your pelvis) Keep your core strong by knitting your ribs together, chest proud and strong, shoulders down.

Foam roll the areas you feel are tight and/or will be needed for your workout.