Carpenters who do their own estimates, how long did it take you to get comfortable with pricing?

I do electrical work and it took me probably two years before I stopped second guessing every quote I sent out. Either I was way too high and lost the job or way too low and basically worked for free after materials.

Curious how it works for carpenters since your scope of work seems way more variable than mine. A panel swap is pretty standard but a custom build out could go in a hundred different directions. Do you guys price by the hour, by the project, by square footage? And how do you factor in the stuff you cant predict like finding rot behind a wall or a floor that is way out of level?

Just trying to learn from other trades guys since we all deal with the same headaches.