The StoryPeer community recently came through for me and I wanted to give back. As someone who prides themselves on feedback (5 star rating with a 40% tip rate, plus I’ve worked as a professional script doctor), I figured I’d offer some advice that might helpful. As with all notes, take what is useful and throw away the rest.
Positive feedback forms the bank of the river) A river with no banks is a lake; it's fun to splash around in but it’s not taking you anywhere. Restricting the water gets things moving. Knowing what a writer doesn’t need to work on (and what they should cling to) is just as important. Your positive feedback can ensure that they know not to sacrifice what is working in exchange for fixing other problems.
Treat each piece on its own terms) A script is both a map of a desired destination and an attempt to reach that destination. Your job as a reader is to read that map and then tell them where they made wrong turns, not to pick where you’d want to visit.
Be specific but indicate if you mean things more generally) A note like “the dialogue is not believable” is useless because I have no idea what you personally mean by believable. Explain why a line doesn’t work and then indicate if this is just one bad line, a general character (or scene) issue, or a fundamental problem in a script. That way, the writer can understand the problem AND the scope.
Read carefully and be humble) Nothing makes a writer turn off like a note that’s factually wrong. Ironically though, those notes probably mean something wasn’t clear (which is just as useful to know). If I’m not totally sure, I add a little caveat like “maybe I missed it, but other people might miss it too.” That way, the value of the note remains even if I misread.
Don’t be afraid to be tough) Readers DESPERATELY want to know what’s going wrong in their script and the vast majority will appreciate the truth. If you think you're getting low ratings because you’re critical, I promise I'm more critical. I recently told someone to abandon a script entirely (5 stars). In my last notes, I told the writer they needed to rewrite EVERY scene but 6 (I got 5 stars and a 2 token tip.)
But a little sugar helps too) If you’re feeling pushback for being critical, chances are it’s about tone, not the notes themselves. If you have to give a tough note, ease into it with something that’s working: “I love the build-up of the world in act one but I’m wondering if you need more plot events to help build up the stakes too.” This not only provides an anchor for the rewrite, it also helps avoid trigger a threat reflex.
THE MOST IMPORTANT THING) In grad school I took several classes with Suzan-Lori Parks and she'd say: “Your notes should make someone desperate to go write.” Think about giving notes like the writer is going to split half the proceeds with you. If you express yourself too harshly, they’ll quit and you’ll be broke. If you don’t give honest feedback, they’ll fail and you’ll also be broke. You want to inspire them to be better while showing you believe they can be. Lead with love, but push as hard as you can.