"Proper" way to wire an unbalanced TRS-to-TRS cable
In the recording studio, TRS plugs are often used for balanced, mono connections. Since you said "unbalanced" (and also because 3.5mm are not usually used for balanced connections) I assume this cable is to be used for stereo, although you can wire it in the same way:


tip &lt;-> tip using an internal conductor
ring &lt;-> ring using an internal conductor
sleeve &lt;-> sleeve using the cable shield


If the cable is for balanced mono, you just want to make sure the internal conductors are right for the job (ie, just make sure it's "balanced" cable). Stereo cable will sometimes run as two separate cables with two separate sleeves.

Some people do various other things with the sleeve connector, including cut it, in the vain hope that it will somehow avoid ground loops. Sometimes this works, but when it does it not the best way to cure ground loops -- in fact it can make them much much worse. At worst, no signal will get through, because there is no return.

As for RF, you could try an RF choke at one or both ends of the cable, I suppose, but I don't know anyone who does that with their audio cables in the studio. RF and audio are far enough apart that they are easily filtered by analog gear.