How long before you trusted your keyholder enough to hand over the key?

I have wanted to try chastity with a keyholder for a while, but I have no idea where to actually start looking. I am not on any kink sites yet, and I do not want to just message strangers and hope for the best.

For those of you who found your first keyholder, how did you do it? Did you meet online or in person, and how long was it before you trusted someone enough to hand over the key? Any beginner mistakes I should avoid would help a lot.