How one could accidentally, while not flying aeros, get a typical modern GA aircraft into a fully developed multi-turn spin is beyond me.
But getting into something slightly beyond incipient is another matter. Do an 'ordinary' stall, with a few less-than-usual or messed up aspects: Stall in a turn, rapid deceleration, power left on, some friends in the back seat, freeze on the controls for a second or two... Good idea? Probably not. Could happen? Def!
I read somewhere something being suggested as a "useful exercise": To fly the aircraft well into the stall, keeping the nose up with elevator, and practice keeping the wings level with the rudder. Great fun, as is the spectacular departure when you finally lose it...
The result is of course not a developed spin, but a tad beyond the normal "recover at warner" type stall drill. I don't think I'll try that exercise again...
What my PPL spin training did for me is to give me more confidence when practicing stalls on my own. I know that even if I somehow make a big mess of it, to the point of actually getting into an incipient, I'm still in well known territory. I don't think I'd want to practice stalls alone, beyond the "recover at warner" stage, having not done spins.