I've been a closeted diaper lover my entire life, not telling a single person about any aspect of my secret. However, a very close friend was visiting me at college from out of state, and I new that she would be the person I would tell. I didn't have it planned out 100% but I knew I had to tell her.
So I basically just told her that I was a diaper lover, and that I enjoyed wearing and ultimately using diapers. She was SO accepting of me immediately! She had an actual interest I feel in the ABDL community and never once judged me. To celebrate, I was padded all weekend. I can't ship good diapers to college, so I had Always Discreet, some Goodnites, and Depends with tabs on hand.
My friend even wore each different diaper at one point to "try it out". I don't think she enjoyed it too much, though, seeing her diaper herself on my apartment floor was quite interesting. I didn't tell her how to put one on, she just went for it. It wasn't too well of a fit.
She (and I) were both paranoid while we wore in public, but she was even more shocked when I wet my diaper in public. Needless to say though, I have now opened up and been accepted! So happy!