What does a best-practice SQL Server maintenance plan look like?
You have to plan it with the business needs in mind.  Sometimes it's a maintenance plan (like when a shop doesn't have full time DBAs or wants a minimum of complexity.)  Other times it's Ola Hallengren's maintenance scripts.  Whatever you do, it has to take into account the business needs for that data.  I discussed it in my post Ozar's Hierarchy of Database Needs.