When you narrate what comedy voice do you try to have? Obviously you should try to be yourself, but there are so many other voices to chose from so you can alter things.
Annette Mills (Goodnight Children Everywhere)
Kenneth Horne
Kenneth Williams/Julian Clary type voice (not to be homophobic, it's just hard to tell the difference)
Dick Vosburgh movie commercial voice
Oliver Postgate children's programmes voice
Stephen Fry (camp but chummy)
Peter Jones (Hitchhikers-overdone I'm afraid)
Michael Bentine professor type voice
Spike Milligan -loony voice
Newsreader type voice.
Auto voice - Mind the Gap etc
Robot - similar but can have an accent
Could also work on cartoon characters etc