A few answers to questions about translating specific Earth idioms.
An buy'ce, nu mirshe: All helmet, no mind.
Ures mirshe, ures urakto mirde: No mind, no problem. Without a mind, without difficult/challenging thoughts.
Ke sur'a: Lock in!
Mandalorians are direct and don't see the need for artificial politeness. Nonetheless, there are ways of capturing the sentiment. Choose the version that is closest to what you mean.
Gar copikla: You're charming.
(This uses an adjective reserved for babies and animals and is an insult to adults.)
Ibac copikla a di'kutla: That cute but stupid.
Gar di'kut: You're worthless.
Vercopa Manda gaa'tayli gar: May the Manda help you.
Some of these hew closer to direct translations of the English phrase than others. Choose which you like the best.
Muun'baj'ye! — roughly means, "This/I teach you a hard lesson."
Ke baj'hib — an extremely informal command to "learn, take education."
Ke jate'shya — a command to "be better."
FUBAR: shabla suum an lisite buyacir (screwed up beyond all ability to recognize)
All that glitters is gold: An meg vutyc cuyi waadasla ra jaon'yc (all that is special is valuable or important)