Attaching talent to your screenplay. I.e., getting an actor and/or a director to officially declare interest in the script to raise the chances of a sale and production. This is very difficult to do without representation (see Unsolicited Submission), and even more so to attach a “star” as their agents will refuse to look at a script not already funded for production. This is also referred to as attaching “elements.”
A major agency (like CAA or William Morris-Endeavor) can put together a package that includes their clients in the key roles (director, writers, leading actors) with partial financing and approach a studio for finishing funds and/or a distribution commitment.
A new writer wants to generate “buzz” on their script in some way that might get name talent to consider it. A contest/festival win, a referral from a friend or existing client or even a well-known true-life inspiration can help to build buzz on a script and get it read.