Edited (version 10)
Retro-fu
Use oldschool tools or retro hardware devices
Having one of those "where's my triangle?" days? Try changing the scene! Try the retro-scene: where people continue to make beautiful things on old, sometimes very old, computer hardware and game consoles and various random / weird devices.
Shian Lee by Bomb - here emulated in realtime thanks to the Internet Archive - watch it with sound on YouTube
We suggest you visit the Vintage Computer Festival to get your hands and play demos on real retro hardware. But if you don't have a 386 PC handy, you can start with retrocode on a modern computer using an emulator or compiler.
A spinning cube in QB64 - code at iquilezles.org
There are also many nice retro-ish things, like the JS Speccy and TIC-80 fantasy console, to play with and code on out there.
THRIVE by Ilmenit / Agenda (source)
The demoscene thrives on productions for the Amiga, Atari, ZX Spectrum and many other makes of computers and game consoles. If there's an oldie-but-goldie platform you're interested in, just ask at the Graffathon for some tips and waypoints!
wolfenMarcherFC by atariBDSM