How do you actually pick a comfortable saddle?

I've got a few different ones for different applications (although 3 of them are SLR variants).
I can get comfy on all of them because:

• I've set them up properly
  
• I sit on them properly i.e. I don't 'sit'
  
• I don't stay long in one position
  
• I'm better than you*
  *'you' meaning 'hippy'
  
  

You're better than my left little toe. But I've never liked that one anyway.
The rest of me.. waaaaaaaay more betterer than you.. waaay more betterer!