When the lights went off, the accompanist kissed her." from Bel Canto, by Ann Patchett
The first line of this novel grabbed me immediately...partly because I'm an accompanist myself, and that word doesn't show up in novels very often. But this sentence immediately created an image in my head - not only an image, but an entire scene is set by those nine words. You can hear the singer's last note, ringing through the hall, see the lights suddenly go dark, feel the accompanist's excitement as he jumps up from the piano and kisses the performer.
First lines are the way a writer grabs the reader from the get-go. Go through your favorite novels and read the first lines. Which ones are the most interesting? How do they get you involved in the book and make you excited to read more? Set aside one section of your writer's notebook for favorite first lines.
Now pick one of your favorite first lines and make it your own - write for 10 minutes using this favorite first line as a starting place.