I will note that for those of us who don’t do this for a living, with the attendant mentoring/training, there are entire books dedicated to the problem of workholding and fixtures. Picked up a copy of Jigs and Fixtures: a reference book showing many types of jigs by Colvin and Haas and agree that it’s rightly described as a classic.
(mentioned at: Newbie: best way to drill some holes in a case )