Preferred option for proceeding

• Something to try first
• Flat surfaces of the skull
• Initial strategy
• It's often backed up
• Strategy to try first
• Preferred way to proceed
• The first thing to try (and hope for the best)

Wikipedia Word definitions in Wikipedia
Plana is a lunar crater that lies on the boundary between two small lunar mare areas, with Lacus Mortis to the north and the larger Lacus Somniorum on the southern side. It is joined to the crater Mason to the east by a short stretch of rugged ground. Due ...