For me, I had to give best to the notions of jiggery when I made the 1/12th scale Maserati "Birdcage" chassis as the front suspension and engine mounts were abstractly in mid air somewhere, so something had to be built to hold the right parts in the right three-dimensional place relevant to all else.
Then there was the front end of the McLaren M8F monocoque. Now that was as abstract a lump as they get.
Looking at this lot now, I cannot believe I invested so much rare and expensive wood in one jig!
But...it seems to have worked.
It actually saves a vast amount of time and IS the professional thing to do after all. At the time I had a bigger response to the pesky jigs, than the models!
I really would love the time to finish that McLaren. It's all in a box in a cupboard, the book full of sketches is still there, but unintelligible and somewhere I even have a real McLaren rear upright somewhere! Alas the real car is long gone to Holland and I have very few photos left from those days... But it would be a good pension pot addition, I suppose. The man from Bonham's once told me around £13,000 when finished, but I doubt models are fetching that these days.