I follow what is on the indside of the fuel flap - Normal load - 35psi. I have tried 36psi and it felt a bit skitish, but that was with Dunlop Sport Max tyres. Then I had Goodyear Eagle F1 Asymmetric 2 and I tried them with 35psi then 36psi and 37psi and no difference. I think they needed at least 40+ psi in them. This was probably due to how they are made - all floppy and ballooney. I now have Pirelli PZero Rosso Asymetrico and run 35psi and I am as happy as larry with them. They feel spot on.
It all depends on the tyre and how it is constructed, the wheel (alloy/steel), the car it is going on and the type of driving the owner of the car is going to be doing can all factor into when pressures will suit and feel correct. Or words to that effect.