How to find Missing non clustered Indexes

Yes, by rolling up your sleeves to some hard work and analyse slow-running queries and see what can be done with them. Query Store is a tremendous asset here, and if you have not enabled it for your database, do so first thing. When it has been on for a week, you can start digging.

The process is, by the way, not any different from identifying missing non-clustered indexes. Yeah, in that case there is a DMV that suggests non-clustered index, but I rarely look at the DMV. It has a fondness to suggest covering indexes. While such indexes can help to improve performance, following those recommendations blindly can result in a number of redundant indexes. And a problem is that what is a covering index this week, may not be next week when a new column is added to the SELECT list to meet business requirements.

If you were asking for SQL Server making recommendations about clustered indexes: No, there are no such recommendations.