My paranoia manifests in the idea that people are watching me and have ill intent towards me and might want to try to harm or kill me. I deal with this the same way that I deal with my other anxiety based disorders.
1. Box Breathing to calm the body's heart rate and physical symptoms. In for 4, hold for 4, out for 4, hold for 4. Repeat at least 4 times, preferably 8 if I have the time. This resets and calms the body and the nervous system.
2. 5 senses task to ground me in the present and divert my focus to what's ACTUALLY going on around me. 5 things I see, 4 things I touch, 3 things I hear, 2 things I smell, 1 thing I taste. Repeat as necessary.
3. The mantra. Pay attention to the thought that you have. Say the mantra, 'That was a(n) [adjective i.e. scary, sad, angry] thought, I wonder what thought I will have next?' This validates the emotion that you're having, it validates the thought itself, and then it prompts the brain to think of another thought. It often takes around 5 to 10 repetitions to get the brain to start actually thinking about other things. Repeat until you have thoughts about other things at least 8 times in a row.
4. Weighted blanket, or piling blankets on top to simulate the weight. The pressure helps calm the nervous system, especially if you put it on top of the sternum.
The big main thing here is that you're not going to want to try to avoid the thoughts, you're not going to want to try to bottle them up and push them away and not think about them because you're only going to make yourself think about them harder. Distraction is fine for a short period of time but it often comes back quicker when you only distract rather than actually validating the thought, looking at it, and then prompting yourself to think another thought.