"What were you doing just now?" or "What are you doing just now?" .... Are these sentences correct or not?---- "What were you doing just now?" or "What are you doing just now?" or "What did you do just now?" or "What were you doing?" "What did you just do?"

Question

"What were you doing just now?" or "What are you doing just now?" ....
Are these sentences correct or not?---->

"What were you doing just now?" or 
"What are you doing just now?" or
"What did you do just now?" or 
"What were you doing?"
"What did you just do?" <--- this is more like angry tone is it?

Which sentences is more appropriate? Or any other examples? I just wanted to ask what the other person was doing before talking to me. :)

Answer

If it's about before, you want past tense:

What were you doing ...  Very general 
What were you up to ...  May be aggressive or not, depending on context and tone of voice. 
What did you just do.  This is aggressive in many cases, but not always.