Not every expiring domain deserves a backorder. A good candidate should have a clear name, commercial meaning, a useful extension and a history that does not create reputational or SEO risks.
Before placing an order, check the domain length, memorability, pronunciation, previous use, backlinks, archived website snapshots, possible trademark conflicts and the market value of similar names.
Short names, generic words, industry terms, geographic names and domains with strong historical authority can be interesting. However, metrics alone are not enough: a domain with many links may still have little value if those links are low quality or unrelated.
For business use, also consider whether the name can become a credible brand. For investment, estimate a realistic resale range and avoid overpaying only because a metric looks attractive.