Thou art a fishmonger.
A pimp of the flesh is more apropos.
Shakespeare is a quote-machine. His insults are unique (at least within our post-modern, acronymically sterilized vernacular) and colourful.
The word-smiths scribing for Madmen are no slouches when it comes memorable one (or two) liners either.
And cinema has been responsible for some of the most insightful, and philosophically profound words to ever singe our ears. They can not be discounted.
Bull Durham: Strikeouts are boring. Besides that, they're fascist.
Heathers: Did you have a brain tumour for breakfast?
Dialogue can leave an indelible impression.
Play with the words of William Shakespeare, the writers for Madmen and the screen-writer for an famous/infamous film, and write something original.
Choose/create a Shakespearean Insult Shakespearean Insult
Choose a quote from Madmen or go on a Twitter hunt for other lines.
Choose a memorable film quote from The Other Best Movie Quotes of All Time or Best Movie Quotes @MovQuotes or AFI's Best Movie Quotes
Read tips for writing a script at BBC: Tips for Playwriting
Experiment with structure of a screenplay or stage play. Review the following:
Crazy Train : a sample script
ScriptFrenzy : How to Format a Stage Play
ScriptFrenzy : How to Format a Screenplay
.... having difficulty thinking of something to write? Try an image. Or find one on your own at 24 Hours in Pictures.
Or simply use your wonderful imagination.