I use both HVLP and classic suction guns... depending on what I'm painting. I have small detail guns, through larger guns with half gallon remote tanks. Anything bigger is hard for me to handle... and I can only spray so long before I need a break from it.
I am not a great painter, but from the school of hard knocks (not doing something right the first time)... I hate sanding. So If I have to strip something down and re-sand it...
Just a few additional tips I've learned--
Make sure you have dry air. You can coil a hose in a 5 gallon bucket with water and ice... before your water separator to help dry your air out (in high humidity).
Make sure you have consistent pressure. Too high will atomize the paint and get too much overspray. Too low will throw drops (too big) onto your work.
Make sure the area and your work piece is somewhat warm. (i've pre-heated some objects in the winter!!!)
Starting out, check your pattern, and how it sprays.
If your position and technique is good and consistent (the first thing to get right, it was discussed previously in this thread)... and you are getting too much over spray, lower your pressure.
If it doesn't lay down right (sandy, pebbly, grainy), use more reducer. It means your finish is not laying down before it kicks, so needs to be thinned. If a spider web or such kind of pattern, hazy, uneven coverage/surface, it means it's kicking off too fast and is too thin.
If it is going to take more than one cup (gun reservoir) of paint to finish a coat, I have someone mix while I paint. They also keep my hoses from messing up my work, and keep an eye on me. That way, I keep a fresh start, to continue, before where I left off kicks.
Use a good respirator with good filters. A dust mask just isn't good enough for me. Use good eye protection that you will just use for painting. Even with DC type of underpressure, some overspray is inevitable, and will ruin good eyewear! (Once you see how much really builds up over time, it will convince you to use good eye and breathing protection!) Wear nitrile gloves.
Make sure there is good, adequate ventilation to elsewhere. I almost lost my little brother, when a ventilator failed in a paint booth at his work...
If while you're painting, you notice your pattern change or the size of your paint particles change, first check your tip to make sure it's clean. Second, make sure the vent hole on your cup is clean and clear.