I am a huge fan of index cards.
I use them for planning out blog posts, storing crypto key phrases, and general note taking.
They fit in the TEWT bag I use to carry things around in.
I can use them to make trains and cars with my son when he crafts.
If I am being honest here, I cannot believe that it took me so long to discover them.
Do you use them?
If not, give them a go.