I started just recently. I decided to try making my own wooden lures, and finishing came as part of it. While researching finishes I came across a bunch of websites where people were custom painting crankbaits. That got me really interested in airbrushing, and the rest is history!
As far as the tips, I'm new at it, but I would take study a lot of pictures of real bitch. Also try and learn about what patterns have been effective historically. Other than that, just practice. Watch some airbrushing videos on YouTube, that should help quite a bit. There are also a number of Videos that are instructional on painting specific types of finishes on crank baits. You can look on YouTube for those as well. Best of luck to you