transposing instruments

[Fodor Bertalan]

I have a practical question about transposing instruments, perhaps you have
some experience.
For example we make a c major score for Flute, Piano and Clarinet in Bb.
What notation should be used for "c d e f" in the Clarinet part?
I think it is natural to use \property Staff.transposing = #-2
So we have to have notes in d major.
What way is better for it:
\notes { d e fis g } -> i.e. write "played" notes (as you see in the score)
or
\notes { \transpose c d { c d e f } } -> i.e. write "heared" notes

(My first guess is that the latter is better, because this way I can easily
put that to other - non-transposing - instruments, I just have to remove the
transpose)

staffClarinetInBb = {   
        \new Staff {
                \property Staff.midiInstrument = #"clarinet"
                \property Staff.instrument = #"Clarinet in Bb"
                \property Staff.transposing = #-2
                \notes { % what should I write here?
                }
        }
}

Thanks,

Bert