I have a thing for egg salad as well as soft-boiled eggs, so I regularly do a dozen at a time, without salt or vinegar or pre-cracking, and every time this is what works...
Boil your eggs to desired done-ness (everyone's varies depending on the number of eggs/pot size/burner setting/etc.
This is the important part:
Immediately remove from heat and drain
Douse/Rinserinse with cold water and repeat until heat is removed - this means until you can no longer feel the rinse water warming up from the residual heat of the eggs. Everyone says this is to stop the eggs from cooking in the shell, but the reason it is critical is because the continuous cold water makes the eggs sweat (cause condensation) between the white and the shell and possibly initiates some slight shrinkage of the egg that assists the separation.
Let sit for a few minutes...
Peeling:
Tap the egg gently on table or counter enough to slightly crack the shell
Place the palm of your hand over the egg, and gently roll the egg forward and back on the table and alternating sides. Apply just enough pressure on the egg while rolling to make it crackle as it rolls. You will know how much that pressure should be because you will feel the shell separate from the egg as you roll it. Too much pressure on a soft-boiled egg and you will break it open.
Pick a loose spot and begin peeling. You should be able to peel off the entire shell in one piece in a matter of seconds. I've often done it in about 2 seconds. Sometimes, depending on how you've rolled it, the shell will just plop off in two halves. It's quite amusing how excited one can get looking for that one second shelling.
Your success depends upon your rinsing and rolling skills as you endeavor towards that one-second shell. Practice makes perfect. Good luck