Meaning: immediately or easily. Origins and mentions.
Rewrite 1: at the drop of a name
Rewrite 2: at the toss of a coin
Rewrite 3: as sudden as a sneeze
Rewrite 4: faster than the snapis3a of a whip
Rewrite 5: easier than licking a stamp

Comment: What else is quick or easy, so quick or easy it will come immediately to mind?

More reading about clichés
What I found when I googled “clichés”:
• John August: “a ton of useful information about screenwriting.” How to avoid clichés in story writing.