Sindarin for motto: "Thought. Speech. Action."

gûl. paeth. cared.

Is that right?

Each of these three words is meant to be in the imperative mode.

So, based on an answer in a different thread, perhaps this would be better?

gûlo. paetho. caredo.

The imperative is a verbal mood; these are nouns.

I'd offer Nauth, paeth, caur (lit. "thought, speech, action").

Great point! Thanks!