It's not just what you say but HOW you say it.
One of th biggest mistakes made in PAs is that the person forgets that they are not talking to one person (ATC) who is wearing high quality headphones - possibly even noise cancelling - and who is attuned to the kind of thing that you are saying.
The most frustrating thing is that the sound is too low and you simply cannot hear what is being said. It gives the impression that you do not care what you say to us.
So think about speaking more loudly than normal becuase we have all the cabin background noise which you do not hear.