Joyce, in my estimation it's really to your benifit to learn the fundamental brush strokes..there's only 2 -- a dot & a dagger stroke--put those with a little linework & the mere practices learning these will encourage & show you what path to take with the airbrush..with everything you say you're doing at the present, you really need this Joyce..
These are the most basic practice sheets..you must learn to make between 12-15 dots in a row without turning your air off.. Remember with a double action airbrush the entire control is handled by the trigger.. Learn to handle the trigger & you're well on your way..You must make these dots all leaving the AIR ON in order to teach you trigger control..easier said than done--start practicing now & then it's on to the dreaded dagger stroke that can be sooo much fun to do..
If you have already learned to do these strokes accept my apology--I'm not sure you stated the level of skill you have with the airbrush..When you can duplicate these practice sheets you can then advance to the actual art of the airbrush..It can be a lot of fun & lucretive too!!
I suggest you practice on Viva paper towels & it's always best in the beginning to practice with black paint..Some people find it pure drudgery but practicing & mastering these strokes will assure you that your aspirations can become reality..