Collecting materials may seem easy to the eyes of veteran players in Genshin Impact as they had already completed most content and have enough Resin to steadily fight bosses and enter domains.
New beginners, however, need to choose their character carefully because they have to farm lots of items before making the said unit a decent DPS / Sub-DPS / Support / etc. The following infographics are created by SoraHoshina (AKA me) on HoYoLAB.
The chart will show which enemies and domains provide the materials for each playable character in the current version of Genshin Impact. Open the images in a new tab for the full size and you may download them. The Traveler has been excluded for simplicity as it alternates each level.
Geo Traveler wants both Dvalin and Andrius for their talent materials.
Traveler is not included in the infographic because they do not need materials from any normal bosses.
Geo and Anemo Travelers need two Common Enemies for their drop materials.
Traveler (Every element) is excluded from the chart because they alternate at each level.