The folks at Desiring God produced this four-minute video called "Don't Waste Your Pulpit" which is directed at pastors.

I think the audience is much broader than that. I think the audience needs to be much broader than that.  I think you can easily change it to:

"Don't Waste Your Bible Study"

"Don't Waste Your Quiet Time"

"Don't Waste Your Sunday Morning"

Or, as the name of the series is called, "Don't Waste Your Life". 

If you lead or are part of a Bible study, this is for you. If you are a Christian who does personal quiet times and reads the Bible, this is for you. If you go to church on Sunday mornings, this is for you. If you are a Christian who doesn't do any of those three things then this really is for you.

Just replace "pastors" with "you" or "people" (for the more timid).

It's a great reminder and encouragement. Don't waste it...