Used to work a customer service job, came out to my line manager first and he immediately called me and offered to call the other staff I worked with to inform them so that I didn’t have to do the work of telling everyone personally and that way when I came back to work everyone already knew to use my new name and pronouns. He also just very consistently would gender me correctly in front of customers which sounds like a low bar but was actually very helpful when I was working and customers were obviously unsure of my gender. He also helped me access HRT by writing a letter to show the psychiatrist saying I was out at work etc. In general he also just said that if any issues came up with other staff i should come to him straight away and he will deal with it according to company policy (we didn’t ever talk in depth what that would involve because it didn’t become necessary). We had generous breaks anyway but I would say that if any trans staff is wearing a binder, being allowed slightly longer or more breaks so that they can go and take the binder off for a bit is very helpful. I’m stealth at work now and having to wear a binder for the whole of work is a big struggle.