Beyond sound & 'spray and pray': Worst festival strategy mistake?

Hey everyone,

I'm Luis, a Location Manager usually, but I just finished a short doc I directed myself. It's about a local community garden project, very grassroots. I poured a lot into the story and getting good, honest interviews.

Now, I'm staring down the barrel of festival submissions. I've read plenty about avoiding the 'spray and pray' method and the absolute necessity of good sound (learned that early on, thankfully). But those feel like foundational lessons.

For first-time filmmakers, what's the single most damaging but avoidable mistake they make in their festival strategy, after they've got their picture locked and their audio is solid? I'm trying to be smart about this and not blow my chances right out of the gate with some rookie error I haven't even considered yet. Any insights would be hugely appreciated.