In terms of unpleasant culinary experiences, the unnerving crunch of eggshell in a cooked meal is second only to finding a hair in there. You've likely fucked up an egg crack more than once in your life. Maybe thinking about the physics of an egg will help.
The perfect place to hit an egg is along its equator, which is the flattest part of the egg. The egg's breaking limit is lowest there, as opposed to its curved ends, which can dispel force more easily. Think of it like an arched bridge vs. a flat bridge, a suggestion courtesy of Popular Science. (The arched bridge can sustain more weight before breaking.) So, make one quick crack along the side of a mixing bowl just big enough for your thumbs, then apply steady force so that crack continues to expand. Don't pull in a jerky way, though—that will make the egg shell shatter. Really, this comes down to confidence: steady hands and ability to apply force.
For extra culinary flair, try a one-handed egg crack: Crack the egg on a flat surface, then pry it open by pushing the top portion away from you with your thumb while pulling the bottom half of the shell away with your other fingers. This technique isn't the cleanest, but it looks cool.
There you go. Because you want to make those pancakes without gritty bits, or whisk up french toast batter without bobbing for shell fragments.
