I was reading a post about muni tire pressures, and I’d appreciate some advice from the trials crowd.
Here’s some info so you can give an educated answer.
Uni: KH 20
Weight: 170 pounds
Tire: The stock luna. Pretty sure it’s 20 x 2.5"
I’m not dropping anything big now, still getting used to the new uni. I also do all of my riding on concrete.
Let me know your thoughts on a good place to start. 
Trials riders generally ride with the tires between 15 and 25. I personally would recommend not going below 20, though it’s entirely a personal matter. Just find one that feels good for yourself. I ride at 24 psi, and I weigh 140ish lbs.
Any more riders maybe closer to my weight?
I’m 180 and usually run about 21ish psi. At least thats what my pump says. I bet they vary. I’ll make the tire a little harder if i plan on doing natural trials with pointy rocks and stuff; maybe 23.
Usually i do some of the things that JC listed in the Muni pressure thread. Ill do some hops and compress my tire and see if it bottoms out. Ill also hop on the pointy edge of a curb if its close by. I like my pressure to be just a bit more than where id bottom out in both cases. Sideways fold is also a good way of determining but i find that if i pass those first two, ill pass the sideways fold test.
I’m sure not everyone is the same. Just keep playing around with it until you find something you like. and remember what it is that you like! 'cause i would find a nice pressure and forget what it was and have to start all over. 
im 78 kg…which i think is around 170 pounds, and i ride with a 35-40 psi. now i get told everytime that this is a crazy high psi to be riding with, but i find that i put so much force into hops, that a lower pressure will cause me to hit rim, or roll the tyre when i sidehop.