There are some improvements to SQL that coincide with the release of XenDesktop 7.x:
Use SQL mirroring because it has the fastest failover (Database HA)
Use AlwaysOn Availability Groups
Use SQL clustering (Server HA)
You must be sysadmin to create SQL databases automatically through Studio
Enable Read-Committed Snapshots on the SQL server database
Please note that you wouldn't necessarily use mirroring and clustering together, you could choose one or the other. SQL mirroring is a technology that increases the high availability of the database by mirroring the databases. SQL clustering is a technology that provides high availability for the entire SQL server instance and is built and installed on top of Windows server failover clusters.