What’s your minimum that you need to just sit down and write?
I need a notebook/journal/document folder and a pen or keyboard. My notebook fits in my purse, and I pack away an extra pen and a pencil. I don’t normally use a pencil, but they don’t run out of ink, so they’re a good emergency backup.
Have your minimum supplies with you so you can always sit down and write some words, a brief stream of consciousness, a ten minute free-write.
Write daily.
And to write daily, be ready.