Most indexing advice is generic. Here are the three strategies that made the biggest difference in production systems I've worked on. Partial indexes for status-filtered queries. If 95% of your queries filter by `status = 'active'`, a partial index on that condition is 10x smaller and faster than a full index. Composite indexes with careful column ordering. The most selective column goes first, but only if it appears in WHERE clauses independently. Otherwise, follow the query pattern. Covering indexes to eliminate table lookups entirely for your hottest queries.