Like you, I went through a long period when boiling an egg that was easy to peel was a hit-and-mystery prospect. Intertubular research coughed up several hairballs and only one gem, and here it is:
Thermal shock. Coming and going.
Bring a pot of water to a full boil.
Take the chilled eggs out of the fridge.
Dunk the chilled eggs into the boiling water. (thermal shock going in)
Boil for 10 minutes.
Near the end of the boil, prepare a bowl of ice water.
At the end of the boil, remove the eggs from the pot and dunk in the ice water. (thermal shock coming out)
Let the eggs cool in the ice water bath for 3 minutes.
Remove and peel, easy-peasy.
Works. Every. Time.
Now, there will be the occasional cracked egg, but that's also true of the methods that don't work as well. Also, when I'm boiling a lot of eggs at once I use a fry basket to dunk them all at the same time.