Sheilded Control Wiring - Tied to Ground or Tied to Common?

In analog circuits you tie all the shields to a common point. If you use coax tie only one end to ground or the common point. This prevents ground loops. You can then tie to earth ground if you have one or power supply - lead or both. All grounds should be at one point and this should reduce the noise. I just did it with my electric guitar and the hum dropped significantly!

There should be a lot of immunity from noise if analog current signals were used instead of voltage signals.

If noise persists, one of the options is to wind the signal cable a couple of turns through a ferrite ring close to the signal receiving point. Another is to program a low-pass filter on the input to the programmable electronic system that is receiving the signal.

Common and ground are not necessarily the same thing, if they are then yes your shielding should be connected to a single point where this is the case .If common is not ground the shielding should still be tied to ground and probably decoupling capacitors placed between ground and common. Some experimentation is required to get the best results.

It depends on the type of noise. The solution for solving EMI noise is the opposite for solving Common Mode Noise. This is something of a nuisance within automotive circuitry. In our case of developing sensors and building in EMI filters between the sensor circuit and frame in which the signal ground is isolated from the chassis ground avoiding such things as (true event) having a Volvo drive by LAX and have radar shut off the car due a failed sensor. Unfortunately this creates a situation that leads to possible problems with Common Mode Noise or ground loops which is solved through tying signal ground straight to the chassis (in automotive applications) or earth.

My company is involved in digital and analog control wiring for buildings and industrial machinery. Our experience shows that landing all source point shields on negative power supply (not earth ground) works best. All shields at the terminal end of circuits should be insulated and not landed at all. We have tried many combinations, and this practice works the best for reducing noise. While many suggest using earth as ground, it is not normally "clean" enough for control circuits.