In Indian dialect, the commonest phrase you find among us is get ready when we have plan to go out. It does not matter whether we are going to party, movie, outside eating or whatever... if we are going out of the home, we use this phrase to tell a person that they should get ready by...
- putting up good attire
- wear some accessories
- do some makeup to look good
- whatever it takes to go out comfortably
get ready, in Indian English will include everything that I mentioned and if you tell this phrase to any Indian while going out, he or she will understand that.
Since I'm keen to learn neutral English I found that get ready is not exactly what we understand. Also, natives tell this way - get ready for the [reason -say party] which makes better sense but then that's not the case. It's just outing and get ready for outing will mean something else and not putting up dress and ..till 4th point.
What natives practice makes utter sense get ready for... but then in my case as I described, it won't make much sense (get ready for restaurant! get ready for the beach!..and so on...)
Again, to clarify, we use get ready in this way...
"Okay, I'm bored; and we are going out. I don't know where but somewhere to unwind.
(After 30 minutes; to my wife) "Ah, what are you doing? get ready...fast." - And, she would understand all those 4 points up there!