Our graphics are hand-drawn. @CaptainTick433 is a pro graphic designer. He’s done a lot of our stuff. Most of the time, I’ll send him screen shots of the instruments I need made and he draws them, then sends me back the resulting Photoshop file with the vector drawn stuff. In the case of the CRJ, we had a guy actually 3D model switches and knobs and he and Tick worked on that together to get them looking awesome.
I’m proficient in graphics (although not an expert). When I make switches, sometimes they’re freehand. Knobs I typically freehand. For more complicated switches, I tend to start with screen grabs for the sim with switches in their various position, then hand-draw (trace) over them with vector drawing tools so that I can keep the proper shapes and proportions. Then I apply textures, lighting effects, shadows, etc. So they look really genuine and 3D in nature. I’ve actually gotten reasonably good now using the drawing tools in PS.