https://www.blender.org/ (for 3-D modeling and animation)
https://www.electropuppet.com/free-adobe-puppet-templates/ (free Adobe CC animation rigs)
https://www.photopea.com/ (alternative to photoshop)
https://firealpaca.com/download/ (free digital painting software)
https://medibangpaint.com/en/ (free digital painting software)
https://krita.org/en/download/krita-desktop/ (free digital painting software)
https://inkscape.org/ (alternative to adobe illustrator)
https://procreate.brushes.work/category/free-brushes/ (Procreate)
https://beebom.com/best-free-procreate-brushes/ (Procreate)
https://librium.digital/ (Procreate)
https://www.brushgalaxy.com/brushes/free/ (Procreate)
https://jaejohns.com/free-procreate-brushes/ (Procreate)
https://www.brusheezy.com/free/paint (Photoshop)
https://www.behance.net/search/projects?search=free+photoshop+brushes&locale=en_US (Photoshop)
https://myphotoshopbrushes.com/brushes/ (Photoshop)
https://www.creativebloq.com/photoshop/free-photoshop-brushes-11121140 (Photoshop)
https://firealpaca.com/material/ (Firealpaca)
https://medibangpaint.com/en/material_kind/brush/ (Medibang paint)
https://conceptartempire.com/free-krita-brushes/ (Krita)
https://krita-artists.org/c/resources/brushes-and-bundles/32 (Krita)
https://imagy.app/free-brush-packs-for-krita/ (Krita)
https://homesthetics.net/free-krita-brushes/ (Krita)
https://conceptartempire.com/clip-studio-paint-brushes/ (Clip Studio Paint)
https://www.clipstudio.net/en/functions/materials/ (Clip Studio Paint)
https://www.brusheezy.com/free/clip-studio-paint (Clip Studio Paint)
https://www.youtube.com/watch?v=nyoDgh62Q-Q (Procreate)
https://www.youtube.com/watch?v=2juwkAgJ6KQ (Photoshop)
https://www.youtube.com/watch?v=DKvZoQ2jViY (Firealpaca)
https://www.youtube.com/watch?v=L48nIiuj4_8 (Medibang)
https://www.youtube.com/watch?v=ubQKVqjfKwE (4 ways to get new Medibang brushes)
Making your own brushes
https://www.youtube.com/watch?v=ewNQky3RjsA (How to make your own Procreate brushes)
https://www.youtube.com/watch?v=xw4I-SD_oPc (How to make your own Photoshop brushes)
https://www.youtube.com/watch?v=hLB2TUlL-mI (How to make your own Firealpaca brushes)
https://assets.clip-studio.com/en-us (clip studio paint assets, including brushes, gradients, etc)