If you have an account with a lot of keywords you probably did a lot of work and research to get all those keywords in your account. But chances are there are a lot of them that aren’t getting a chance because their bid is below first page CPC, and you may not even know which keywords those are. Set up a rule to get those keywords onto the first page to see what they can do. On all campaigns set up a “Raise bids to first page CPC when…” rule.
For a big performing campaign, maybe a brand terms campaign where you always want to be on top, set a rule to increase bids every time your ads go below position 3 by choosing “Change max CPC bids when…”.
Then to optimize keywords based on conversions set up another “Change max CPC bids when…” rule so that if a keyword has a CPA that’s too high it gets bid down, (I also made it a rule that it has to have at least 2 conversions before I start bidding down, everyone deserves a second chance right?)
and if it has a low CPA it gets bid up.
Also for those keywords that just keep spending and never convert, set up a “Pause keywords when…” rule that says once a keyword has spent a certain amount and still hasn’t converted, it gets paused.