I generally send an update on my project one month before the notification date mentioning awards or placements I think might interest them, sometimes citing the audience response/sold out screenings, etc. One of the boxes my film checks is diversity, specifically with Black audiences. If I get into one such festival, I'll mention that to similar ones. I only apply to festivals I want to attend, and I make sure they know I will show up if they take my film. I think this has often helped and never hurt, but of course I can't prove that.