I've found that usually I'm waiting on FOH to start, as opposed to waiting on my cast.
Last year, I was calling a thesis play for the grad school I worked for that was being done on the mainstage of the LORT theatre it was attached to. I learned quickly that if I called a true everything, we'd be on track for starting at X:05, which was usually when house management was ready. I'd call 1/2 hour, inform house management that I was calling 15 over the walkie talkie, check with house management to see if I should call 5, check with house management to see if I should call places, and do a final check in with house management to see if I could start.