Various arts

• Color palette generator
• Color picker
• Interior design course
• Pixel art tutorials

Color theory

• Balance in colors and values
• Chromatic fringe
• Cohesion within compositions
• Cohesive but still contrasting
• Color and composition
• Color temperature and depth
• Composition tips
• Light and color tips
• Not Sorry Art (she has some videos where you can see her process)
• Understanding shadow colors
• Values and composition

Drawing and painting

• Artgraphica
• Ctrl+Paint
• DragoArt
• Drawing faces
• Drawing faces (the other one)
• Drawing facial expressions
• Drawing gestures
• Drawspace
• Free drawing lessons
• Google Cultural Institute
• WetCanvas

Figure studies

• AdorkaStock
• Adorkastock's Deviantart
• Anatomy for artists
• Andrew Loomis books (all free)
• Constructive anatomy
• Fatphotoref (password protected, you can dm the creator for the password)
• Figure drawing for artists: making every mark count
• Figurosity
• Force: Drawing human anatomy
• Jookpub stock
• Joshua Jacobo
• Morpho books
• Scott Eaton's bodies in motion

Fiber arts

• How to crochet
• How to knit
• How to sew

Free alternatives to major Creative Cloud programs

Free music and sound effects

• SoundBible
• YouTube Audio Library

General art tips

• Digital inking tips
• How to hold and control your pencil