When possible, perimeter seat with view of main entrance, access to 1-2 exits, table instead of booth, scan nearest current patrons for possible threat and closest hard cover. Pretty much an automatic mental process I go through in public places.
I’m a little surprised there has been no mention of cover, which I consider to be important. It may be better to achieve hard cover than join the crowd at an exit. For this reason, I pay attention to the kitchen door location – most kitchens have stuff to get behind.
A lack of planning on your part does not necessarily constitute an emergency on my part.