The Segmentation Analyzer

Help me segment this data to find meaningful groups.

The data: [DESCRIBE — CUSTOMERS, TRANSACTIONS, ETC., AND THE VARIABLES]
The purpose: [TARGETING / SERVICE / PRODUCT / PRICING]

Provide:
1. The variables that should drive the segmentation for this purpose
2. A sensible approach (rules-based tiers vs clustering) for my situation
3. The segments it would likely produce and how to describe them
4. How to check the segments are real, distinct, and actionable
5. What to do differently for each segment

Warn me against segments that are statistically neat but useless because I
can't act on them differently.