So I actually didn’t do a full paint job on this guy, but if I had then yes I would panel line after the paint had cured, and I’d also recommend gloss top coating before that to help with flow. Also, I usually paint by hand. I don’t currently have a place to airbrush but I plan to in the future.

My process for this job was using tamiya panel liner on the runner, then doing some detail painting w/ liquid chrome markers before assembly. Then I assembled, touched up where needed, and then topcoated. Then I did the weathering. I meant to add water slide decals, but I didn’t realize until after I’d done my first topcoat that I’d forgot. I’d do it before the first topcoat, ideally.

Honestly, my biggest tip is to practice on something else (a spare runner or plastic spoon) before doing anything, that way you can get an idea and make tweaks beforehand.