good patterns and practices about IIS

Hi mister,

any good patterns and practices about  IIS: WebSite, Applications, Virtual Directories, AppPool?

aspnet 4.7.1 and IIS (Windows Server 2012 R2)

Now, we have in a client 51 apps in Default Web site with the same DefaultAppPool.

Better all sites in Default Web site with the same DefaultAppPool?

Regards