Ctrl+L is good because it's on the home row and typically used for uninteresting stuff anyway (like refreshing the terminal window).

My sequence to actually refresh the window is "Ctrl+L L"

I would find Caps+a very difficult to type (since it uses the two weakest fingers). Have you ever tried Caps+d or Caps+f?

I do ctrl+o because I hated having to hit ctr+a two times to go to the beginning of the line in console apps.

This is also what I do.