Firewall PF set

The "best settings" are those that best meet your specific needs. For most users the "best settings" are the default settings.

About the application firewall - Apple Support

Block connections to your Mac with a firewall - Apple Support

Change Firewall preferences on Mac - Apple Support

If you have a desktop Mac at home behind a good router with WPA2 Personal wireless security and a strong password your don't need the Firewall activated.

However, if you have a laptop Mac and access the internet frequently from public WiFi networks then you should enable the Firewall. I can't help you on the settings as I'm sitting behind a very good router at home and don't need it.

Best for what?

A firewall is a network management tool used to isolate parts of the network (devices, users) from other parts of the network.

So, you would need to explain what devices and users you want to isolate within your network.