The mistake many StoryTellers (screenwriters/filmmakers) make is trying to build a career on the back of one script or film. While one script or film can get you in front of agents, managers, producers, and buyers, it just gets you in the door. Without more scripts or projects at least in mind, how will you answer the question: "What else are you working on?"
A key to success is having a portfolio. Finished scripts, ideas for more scripts, completed films (any format), and ideas for your next project. The more scripts you write and the more projects you make, make you a better StoryTeller. While one script or film can be a breakout piece, what's your plan after your big break? Multiple scripts or projects give you something to leverage in these meetings. Having more projects lets people know you are serious and someone they can build a relationship with.
So, StoryTellers, take your time to build your portfolio; it's a key to building the career you want.