A tip that I use.
I show people the planets, clusters, nebs and some very distant Milky Way objects.
I then ask them if they want to see something in another galaxy.
YEAH!!!!!
Then I show them Tarantula.
WOWWW!!!!
Even though it is about the same wow factor as the stuff in our Milky Way they say a bigger WOW just coz it's in another galaxy.
THEN I say "want to see galaxies even further away?"
By this time they are nearly wetting themselves!
At this piont I should ask if they would like to buy a telescope
I build each object up by distance.