Dark Souls 3 – Ghost Trickery

Casting the Hidden Body spell while wearing the White Ring makes you appear as a ghost very similar to the apparitions from other players.
Adding the Slumbering Dragoncrest Ring allows you to get rid of the sound your character is making.

Other useful rings for this are:
Obscuring Ring
Lingering Dragoncrest Ring (extends the length of spells)

Now you even have to fear the ghosts.

Music:
Untitled
Undertale – Ghost Fight [Ghost Remix]
Digimon Adventure 02 OST #10 – Bolero (Type 2)
Persona Q OST – Takoyaki
Undertale – Ghost Fight 8-Bit Remix