Festival Strategy: Single Most Damaging, Avoidable Mistake for First-Timers?

Hey everyone, I'm a working Director/Writer, and I've just finished up post-production on my latest short film. It's a drama, pretty dialogue-heavy, and we put a lot of effort into the sound design this time around after learning some hard lessons on previous projects. Distribution is the next hurdle, and I'm diving deep into festival strategy. I’ve seen general warnings about 'spray and pray' tactics and heard countless horror stories about bad sound. But I'm trying to be really proactive here. For a first-time filmmaker, what's that one universally damaging, yet totally avoidable, mistake when it comes to their festival strategy? The one that sinks their chances before they even get started?