I will focus on the neutral position as that is where I think I am best at evaluating.
Right now you are all straight forward with not a lot of motion or angles. I would work on some basic shadow wrestling to get comfortable with this. You should never move in one direction for too long. I personally have a lot of motion when I wrestle this helps with both my offense and my defense. In terms of defense I am not a stationary target as I am circling, level changing, moving forward, backward, hand in his face, pushing, pulling, snapping etc.
My coach in college was a light weight olympian and his big thing was that when tying never have our hands in resting in one position for more than a few seconds. If you in a collar tie dont sit in a collar tie for too long or the oppnent will use it against you. Every time I touch the guy it is for a purpose and it is to get him off balance, create an angle, and set up an attack.
If you are directly in front of an opponent in a tie up and you just try lower your level and shoot chances are he will see it coming and will be able to defend it. But if you are creating motion, moving his head, and creating an angle before attacking a leg your chances of getting in on a deep shot improve.
I would start with getting in your stance, staying light on your feet and moving in a circle. Once you feel comfortable moving in a circle start to move forward, now that you are circlign and moving forward backstep to get you imaginary opponet to come towards you. Once you get comfortable doing these motions add in some level changes, level changes help keep him off balance as its almost like a pump fake but when you do committ to a shot you need to make sure to level change first.
You can start to add in these motions while drilling with a partner. Get comfortable moving in different directions and moving your partner in different directions so that you have your angle before shooting.
A lot of these is still hard for me to communicate through writing so I apologize if it does not make sense. If it does make anysense I think starting out by increasing your motion and learning how to create angles before attacking is a good start.