In 1967, a book called "The Cartoonists and Gag Writers' Handbook" by Jack Markow was published. It described various techniques for writing and drawing comic strips, especially single frame comics with a witty caption.
Markow explains that there are three main archetypes of these kinds of comic strip: The Hidden Element, where the reader can see what the protagonist can't; The Reversal, where a character says something unexpected; and The Understatement.
He also kindly lists, across ten pages, a number of potential punchlines for single-frame comics. I was surprised at the idea of listing punchlines with no context. I was also surprised at how well these sentences suggest potential comic strips by themselves. Here are my favourites.
Why don't you watch where you going?
What time does the main feature start?
I just washed my hair and can't do a thing with it.
You mean, this old rag?
Am I boring you?
Pretend you don't notice him.
I can lick him with my eyes shut.
Why don't you pick on someone your own size?
Take your dirty hands off me!
Get a load of this.
Of all the things to stuff down my throat.
Unaccustomed as I am to public speaking...
It's the eternal triangle.
Lately, I've felt we've been slipping apart.
Funny weather we're having lately.
Where is everybody?
You hold down the fort while I'm out.
Sir, you're speaking of the woman I love.
It's been done.
She reminds me of someone but I can't think who.
A simple yes or no will be sufficient.
I'm just browsing.
I think Dobson is overstepping his authority.
It's a boy.
This is just one of those days when everything seems to go wrong
Break it up, fellas, break it up.
Where were you on the night of Jan 22?
Markow, J., (1967) "The Cartoonists and Gag Writers' Handbook," The Writer's Digest