How to Use a Colon the Right Way

When you use a colon to introduce a list, make sure to write a complete thought first. Your lead-in should be a complete thought.

So:

Wrong
Next year, we must increase crease our marketing in: the West, the Pacific Northwest, and the Southern regions.

Right
Next year, we must increase our marketing in three regions: the West, the Pacific Northwest, and the South.

Notice how the complete sentence does a much better job of helping the reader anticipate how the expression will end.

—Richard Lauchman, Punctuation at Work: Simple Principles for Achieving Clarity and Good Style