Paletton - Make color palettes and see what colors look good together! Also great for web design!
Want more dynamic panel formats for comics? Here's a cool lil generator to help you out!
DesignDoll - Make your own pose reference with 3d models (or make horrifying abominations)
Krita is another great free art program, though I don't know how to use it ;P
Notepad++ - Edit your codes with this instead of spamming the Neocities activity
Zine maker! (free but please pay for it to support the creator) - A4 paper