Best practice to Share Office 365 Calendar from Outlook

[Andy]

Here is the proper way to do a Calendar Sharing in Outlook (Including How to delegate access properly)
File -> Account Settings -> Delegate Access -> Add (‘Person Name’) -> Calendar (Select desired access level)

On the other side, open up Calendar -> Open Shared Calendar -> Enter (‘Person Name’) -> Open.

This might works on Exchange too, but we never tried with this way.