channels are the most active places to find "just-released" packs or request updates to older ones. DDNet Forums
GitHub Repositories: Many serious modders host "HD Texture Projects" on GitHub. Searching for "DDNet HD tilesets" will often lead you to high-resolution packs that are updated to support the latest game client features. ddnet texture packs updated
A comprehensive repository for Teeworlds and DDNet assets, categorized by skins, mapres, gameskins, and particles. channels are the most active places to find