MySQL indexes?

I recently converted all of the rt2 tables to type=innodb.

I’m interested in doing anything I can to improve RT’s performance - not that
performance necessarily sux - just want to make the user experience as
painless as possible.

I recall a few blurbs in the FAQ, and on the list about indexing certain
tables - but not sure which tables/columns would be best to index. [MySQL
newbie…]

Has anyone played with indexing to the extent that they could recommend a
generic list of tables/columns that would benefit from indexing, or is the
exercise very site specific?

Are there benchmarking and MySQL performance management built-ins or add-ons
that can tell a dmAdmin what to index, when to index, and how often to
re-evaluate the system?

TIA,

Drew M. Mooney