Do it yourself! This is what we practiced today. This is like a pretty rude order, say when making a retort to someone trying to boss you around and you tell them:
“придумай сам” “сделай сам” “Иди сам”
“Think it yourself” “Do it yourself” “Go (there) yourself”
“Keksi itse” “Tee se itse” “Mene itse”
We have three nice second person imperative forms and “сам” for self, -self
придумай - to think, to devise (imperative) - keksiä, keksi if imperative
сделай - do (again, imperative) - tee (base form is tehdä)
Иди imperative of идти - to go - mennä