In all of your twists, see if you can focus on twisting with the torso, from the belly button up. Sometimes we can begin to twist the hips when we go a little too deep, so if you feel this happening, simply pull out of the twist slightly and square off the hips.
For Seated Twist (Ardha Matsyendrasana), focus on extending the spine as you inhale and twist as you exhale. Booth booty cheeks are on the Earth and ensure your front foot is still firmly planted into the Earth.