If those are your first baits man you are well on your way! They look great. In my day job I am a network engineer so I can appreciate the fact that you used the two sides from an old computer case for your painting booth. That's awesome man:) You have for sure found yourself in the land of bait makers here. Everyone here is extremely helpful and listening to their advice will only make you better at this amazing hobby.
There have been so many good tips provided here and I'd like to give you a couple as well. Just a couple of tips to make things easier for you I guess. I used to have HP printers almost exclusively. Every time I would buy ink it would come with a free pack of 4 x 6 photo paper. After years of buying ink I had so much of that stuff it was ridiculous. Once I began making baits I needed a way to mark a center line after cutting a blank I had drawn out. I remember using a stack of CDs to do this at first but they had a little ridge at the center which made them uneven and therefore pretty much useless. Then I noticed I had a stack of unused HP 4x6 photo paper laying around. To make a long story short, you can mark the center point on a bait when it is still in "block" form and then lay a pen or pencil or marker or whatever on a stack of photo paper (or really any paper will work) and then just add or remove paper as needed until your pen or pencil meets the mark. When it does just push the bait around the pen or pencil until you have an even line all the way around the bait. This will give you an exact center line with which to drill your hook hangers, line ties, etc. Getting things exactly center becomes much harder once you have cut the rough outline of you bait and then sanded it to shape so for me at least this method has been a great help.
Second tip: When airbrushing, you can use a transparent base, I use Createx Transparent Base, between coats of paint to help mitigate errors in airbrushing. For example, for me airbrushing is still the most error prone part of the entire process. You spend a good amount of time designing, cutting, sanding, etc., then, once you have all of that perfect you begin the airbrushing process. The airbrushing process is tedious and has many steps depending on what it is you are trying to do. What I have found helpful is to use Createx Transparent Base between steps to protect the layer I just painted from overspray or other errors I make during the next step in the process. So, for example, lets say I've got my base coat down and I have my scales painted and I want to begin painting gill plates. I'll use the transparent base over the entire bait before moving on to the gill plates. Doing this means I have a protective layer over the base and the scales. This way when I begin painting the gill plates if I make a mistake I can easily correct it using a Q-Tip and a bit of water to wipe it away without worrying about wiping away the base coat or scales.
I am no expert but this has saved a ton of time for me and has proved a go to method when airbrushing detail.
Anyway I hope this helps. Great to have you here and welcome to this unbelievably amazing hobby!