Follow the stops in order, island by island through the trials and grand trials to the post-game. Each Pokémon is listed at the first point you can reach a place where it appears. Surfing and fishing spots count from Lana's trial, when you get the Lapras ride and a fishing rod. Tap a row to check it off. Evolves into shows later stages and how they evolve.
Shiny Charm: catch every Pokémon in the Alola Pokédex (Magearna and Marshadow don't count), then talk to the game director at the Heahea City hotel. You'll need trades for the other version's exclusives.
Zygarde Cells and Cores
Alola has 95 Zygarde Cells and 5 Zygarde Cores. Collect them in the Zygarde Cube, then assemble Zygarde at the restoration center on Route 16: 10 make its 10% Forme, 50 its 50% Forme, and all 100 a Zygarde that can take its Complete Forme. Some cells only appear by day or by night. Each Core teaches Zygarde a new move.