A little rule of thumb...
If it's PIC fault then say nothing much and be curteous and re-assure.
If ATC/traffic issue, then you can afford to be slightly levitous, though one person I know went over the top with 'all that were left were the disabled spaces and we have to wait'.
At all times re-assure. A GA is absolutely routine and should never be sensationalised, however, the announcement is VERY secondary to the safe execution of the GA.