Now that it's officially fall - too late for anyone to profit from this little nugget - I want to share a piece of wisdom from my current job. Submit your spec scripts to agencies in the summer. Yes, it is true that nearly everyone is on vacation in the summer. That person who isn't on vacation? That would be the lowly script reader.
During the fall, winter and spring, agency readers are busy, busy, busy with piles of lovely submissions. In the summer, not so much. But we still need something to read. So the agencies, bless them, put out the nets and find scripts somewhere. And a lot of those scripts are (saying this gently) not very good. And it is just barely possible that - in the face of all that not very good - a normally critical reader's standards could slip. A script that might otherwise get a "no" gets a "maybe," and a "maybe" gets a "yes," and a script that's actually good gets a reader singing and dancing down the halls demanding that somebody make that sucker right now!
I exaggerate. A little.
Still, if you've only got one person you can strong-arm into giving you an agency recommendation to get your precious, precious baby over the transom and into my bin - consider doing it in the summer. If you write that script in readable English, I will love you. In the fall, I make no promises.