How do you greet people in your life?

How do you greet people in your life?
Is it different for different people?

When I meet some people in the morning, especially my friends, I say to them " Ohayou"

And When I meet in the afternoon, I say to them "Hi" and in the evening I say same greeting "hi".

But as for when I meet my teacher, higher ranking people or the people who I have not ever met, I would like to use polite way to greeting, for example , in the morning is "Ohayougozaimasu", in the afernoon is "konnichiwa", in the evening is "konbanwa".

How so and why?

Because we express respecting to them for using more polite way to greeting.

Do you touch people when you talk to them? Why? Or Why not?

I don`t think so. But however I touch my friends when I met and talk to them.
Because they are my friends. Hence, in my situation, I only touch people who are close.