When you have a sensor with an analog output on one board, and an analog-to-digital converter (ADC) on another board, what's the best practice in connecting them together? For example, if you have a single-ended signal, should you twist that signal with a GND wire in the board-to-board cable? If it's a differential signal, should you twist the + and - signals together in the board-to-board cable? Or should the + and - signals each be twisted with a GND wire in the board-to-board cable? What are the best practices / rules-of-thumb / guidelines in this area for getting best results? If the answer is "it depends" then what does it depend on, and what is the decision making process for determining the right approach in a given context?
Obviously (?) first prize is integrating sensors and ADCs onto a single PCB, having a nice solid GND reference plane, and having routing discipline to separate your analog and digital domains, if that's possible. But I'm focusing on cases where it's not possible to do that.