You say "usually", so I assume googling forums for similar design decisions and having internal discussion within myself can count, without having a crowd of fellow programmers physically beside you? If you're capable to hold such an internal reflection, then basically you can "google for experience"
Which is reasonable. I’m making it explicit for the sake of the perplexed.
I’ve found myself previously asking, “how do I learn to estimate?” Only to hear, “by experience”. It left me thinking for many years that I couldn’t also learn by having conversations about people’s experiences.