Per the CDC even in restaurants that only do outside seating there is still the elevated risk of spreading and contracting the virus. For you brave inside diners this is what restaurants do or are asked to do. Caveat emptor. Enter at your own risk. You have been warned. Do whatever you want. What could it hurt?
Frequent hand washing
Mandatory mask wearing
Spacing tables and stools
Limit party size and occupancy
Avoid self-serve stations
Restricting employee-shared spaces
Rotating/staggering shifts
More frequent cleaning
New ventilation systems