A complete list of existing manifestos is here, for your reference. Feel free to claim a character, ship, or fandom that's already been covered, but please try to offer your own take on the thing and avoid re-posting stories that are already in our archive.
Once you've made your claim, compose a blurb about why it's awesome, read and round up as many new recs as you like, and post away! The template is below to make your life easier—just cut and paste the HTML into an LJ post or Tumblr submission for easy use. The deadline for your Manifesto Challenge posts is April 30 by the end of the day in your time zone. We'll do a round-up to highlight everyone's manifestos after that—and if you can't join in this round, remember that we're always open for new manifestos.
A few other notes: If you want to center your recs around a particular theme or trope, go for it. And bear in mind that there's no set number of recs you need to include in your manifesto—we've included space for ten as the default, but more than ten is wonderful! And fewer is just fine, too. And if you're doing a character- or fandom-specific manifesto, feel free to include multiple pairings.
stars_inthe_sky: Character, Terminator 'verse, Sarah Connor
blithers: Ship, Life With Derek, Casey/Derek
punch_kicker15: Ship, Buffy the Vampire Slayer, Rupert Giles/Willow Rosenberg
tree: Ship, Star Trek: Voyager, Kathryn Janeway/Chakotay
earnmysong: Character, Doctor Who, Clara Oswald
vickysg1: Ship, Murdoch Mysteries, Julia Ogden/William Murdoch
jazibelle: Ship, Seven Deadly Sins, Diane/King
argylepiratewd: Fandom, Forever
mirime_vy: Ship, Miraculous Ladybug, Marinette Dupain-Cheng/Adrien Agreste
skysamuelle: Ship, Sailor Moon, Usagi Tsukino/Mamoru Chiba
skysamuelle: Ship, Gossip Girl, Blair Waldorf/Chuck Bass
seren_ccd: Ship, Daredevil, Karen Page/Frank Castle
irony_rocks: Ship, Captain America, Peggy Carter/Steve Rogers
skysamuelle: Character, Lord of the Rings, Galadriel
skysamuelle: Character, Buffy the Vampire Slayer, Spike
lost_spook: Character, Spooks, Ruth Evershed
skysamuelle: Fandom, The Magicians