How do you know what a good index is?

Question

When working with tables in Oracle, how do you know when you are setting up a good index versus a bad index?

Answer 1

Here's a great SQL Server article: http://www.sql-server-performance.com/tips/optimizing_indexes_general_p1.aspx

Although the mechanics won't work on Oracle, the tips are very apropos (minus the thing on clustered indexes, which don't quite work the same way in Oracle).