Andrea James suggests in her course calling businesses or customer service lines to practice femme voice.
What are some good places to call where you will get either sirred or ma'amed right off the bat?

Customer service lines are great places to practice. I practice on friends and they actually are pretty nice about helping me. I find that the later the day gets the more tired i get, and the old muscle memory kicks and the deeper i get. I try to make my voice even more feminine then i normally do at places like coffee shops, to me that is good practice.

You can do this even if you don't live FT like me, because on some level people know there are "men" with pretty feminine voices. Since going FT, i am putting more and more emphasis on my voice.

For me practice makes not exactly perfect yet but it is coming. This week at the voice therapist I was able to sustain a conversation for 20 minutes 80% within range of my f3 - 175 htz goal. I then went over to 5 Guys and ordered my burger, in my female voice. I got funny looks but who cares. I'll probably never see them again. I use a guitar tuner to determine pitch and it is really helpful. My speech therapist sends interviews of celebrities for me to study. She sent me a couple of interviews with Sally Field and Meryl Streep to study for cadence, mannerisms, humor. It definitely is a marathon and not a sprint.

I used to travel a lot so I would use the down time traveling in a rental car, driving across NC, to practice.  I was a fan of Andrea James.  I actually used a phrase of here's to practice with: "Hi, this Andrea, I thought you'd like to hear a little bit about what I sound like".  I imitated it over and over again. .  for miles.  I was also a fan of using the drive-thru trying to get "mammed" with only my voice. . .  I was in a production of the Vagina Monologues once.  I rewrote the part to include a bit of my own history and actually used the Andrea James phrase in it. . . I was a Bass in choirs for years and now sing in a Women's Choir as an Alto 2. . . .

Thanks.  Drive thru's do sound like a pretty good place to do a real life acid test.  I never eat fast food, but I'll have to try ordering stopping there for drinks. That should be harmless enough.