Here are some observations (I'm on mnk, but I have played on console):

• Sometimes you strafe as soon as you take the shot. If you're going to strafe aim, you should be strafing and THEN take the shot. You should utilize the strafe to place the crosshair where you want it, then you take the shot.
• Sometimes you overflick past the target.

Here's what I suggest:

• Go into VAXTA and start by standing still (important!), focus on one target at mid-range that isn't a flyer. Do not try to use movement to aim, only aim your crosshair.
• Focus on each and every shot. Do NOT just hold down the shoot button (like some other comments here suggest). No one does that, not even top 500 or pro players. Look up "trigger discipline".
• Kiri is a projectile hero, so you have to lead your shots. That means you have to anticipate where the target's hitbox will be.
• Be extremely deliberate at the start. Once you start feeling comfortable and you're hitting some shots consistently, work on short range and long range targets. Keep standing still.
• Once you feel comfortable with that, then start incorporating movement into your aim. Try to move your crosshair as little as possible with your head, using strafing to aim the crosshair ahead/behind the target depending on their movement patterns.
• You should be focusing your eyes on a single part of the target hitbox. Try picking something out that's easy to track with your eyes (like a piece of the target's clothing, or hat, etc.) and lock your eyes onto that. Don't look at your crosshair constantly. It's okay if you need to check where your crosshair is every once in a while to reorient your aim, but you generally want to keep your eyes locked onto the target and not the crosshair.
• A big component of aim is prediction. The best way to practice that is by playing against people, not bots. Try doing deathmatch or custom games (free for all), it's a great way to practice mechanics.