There are people who don't just use the edge of whatever vessel the egg is going into?

I use flat surfaces after learning it tends to leave less shell bits than doing it on an edge

Yeah, I just do mine on the countertop.

Edge of teacup, then into teacup to check for blood or shells.

I get a bowl and crack it on the outside of the bowl (not the rim) then put it into the bowl to check for shells before it goes into wherever it needs to be.

I crack my eggs on the cutting board, and if I'm feeling fancy I might even attempt to open them one handed!

Bowl, counter, spoon/fork/knife, rim of pan.

Just whatever is handy st the time.

I crunch it in my mouth and spit it into the pan

Smash it on my forehead. The egg goop runs down my face into my mouth. I eat the egg raw, shell and all. Then I do a primal yell and bust out another set of 20 reps. #legday

Flatter surface = better crack

I drop it on the pan to crack it.

If I'm doing more than one cracking two together is best. For the last one, countertop.

I get the flat, inside-the-sink idea. But I'd want to clean either way, and I clean the counters more often than I clean the sides of the sink.

teeth

I'm a corner of the sink man myself. Sometimes the counter top if I get lazy.

I typically use the edge of a knife to crack the eggs, not a very sharp one but sharper than a butter knife. It makes the shell open much more easily and without shards than it would when taping on a bowl or the counter.

A complicated hand gesture in which I hold the egg between my forefinger, ring finger and thumb and flick it with my middle finger.

What? Not everyone dissolves the eggshell in citric acid? /s