Master maker, cartoonist, author, and artist Tim Hunkin spent his pandemic downtime producing a series, “The Secret Life of Components”, to introduce designers and builders to the bits and pieces he uses in his fanciful machines.
One of Jerry Pournelle’s laws applies to those times your electronic equipment or scientific experiment produces a result that defies explanation: “It’s probably a cable”. To this, one might add the corollary, “If not, it’s likely a connector.” Connectors are, as Tim Hunkin notes here, “fiddly, unglamorous, and rather frustrating to use”, but “essential for maintenance, testing, and replacing parts”. Any connector is likely to eventually give you trouble, but choosing the best one can avoid many of the most common problems.