"He looked a mess" wäre ein Vorschlag

"to look exhausted" würde ich sagen

After a long day of work he looked pretty grounded.

"crocked up" wäre meiner Meinung nach zu vulgär...je nach Zielgruppe sag ich mal...

he/she looked worn out

is the expression most familiar to my ears

A little kid would say somebody looked "pooped" (I had to laugh!), but here the sentence is about someone at the end of a long workday. He may look pooped to his little daughter, worn out to his wife, and totally exhausted to his neighbor.

@ Sue , "I am pooped" is quite a common expression in grown-up circles. Little kids don't even know what that means. You may check on that in LEO.

I agree with Sue. "Pooped" my be used in some grown-up circles, but it is certainly not an adult or particularly mature expression!