Oh yes, the ominous fade. Never end a remote conversation with a cheery "Goodbye", or "Later", or "Talk to you next time!" Not when you can cut the communication off in a dramatic or foreboding way.

Phone conversations, radio links, conversations with your co-adventurer around the corner, palantíri, even scrawled warnings on subterranean walls - all can be cut off abruptly and ominously. And the worst thing about it is—

Transcript

Palpatine: You know, you are right; it takes a firm hand to exercise restraint.
Darth Vader: Restraint is for fools and Rebels.
Palpatine: Long ago, the Jedi were taught restraint; I can see it has been forgotten.
Darth Vader: The Force must not be leashed.
Palpatine: <sigh> Anakin was to bring balance to the Force.
Darth Vader: And is there balance?
Palpatine: Not yet; your daughter's powers must be restrained. She must become a Jedi.
Darth Vader: Jedi are too weak. I will teach her new ways.
Palpatine: Your ways are a blight; your blood is thick with corruption. If she does not learn the Jedi way, she will end up...
Palpatine: ... like you.
{beat, Palpatine fades away}
{beat}
Darth Vader: I bet none of the Rebels have to deal with crazy ex-Jedi.