Nothing like writing a long post, hitting back by accident, and losing it.
Sort version (I originally credited people for their posts, I assume you know who you are )
This all comes down to manipulating light, be it heat, radar, visual, but it is all light.
1) Visual cloak (look ma a romulan warbird!). Lots of energy needed to do this -- it takes the gravitational pull of a singularity to bend light like that.
2) Active sensor cloak. This is hull shape and material to reduce the profile of the object from things like radar. A massive ship could be made to reflect like a small meteor, but someone watching their sensors might notice a meteor isn't going in a strait line. Newtonian physics would help here as a stealth ship could just coast.
3) Passive sensor cloak. Everything emits heat and space is an awesome insulator. The iSS has radiators on it, without it the internal temperatures would cook the astronauts alive. There are a couple of methods to reduce this. Reduce or turn off sources of heat, such as power (photovotaic solar power would still be fine), and heat sinks. In the Expanse books there is some mentions of the martian stealth ships using heat sinks to store the heat generated by the ship and its crew. Eventually that heat has to be radiated out, making it very visible to this sensor type. These heat sinks are also very massive -- this is counter to the quick and lithe trope for stealth ships. If you want and quick ship then you wont have the mass for anything else.
To expand on the white noise concept, in the Expanse books ships were also equipt with IR and radar lasers, not to cause direct damage but to blind the other ship sensors.