From "Nancy Drew's Guide to Life" by Jennifer Worick

When searching for important clues, anything labeled "top secret" might be a good place to start. "The Crooked Banister"

Spend time at the gym to build upper body strength. Detective work may require fending off a vicious hair pulling. "The Thirteenth Pearl"

Being able to throw your voice can get your unskilled assistants out of tight jams. "The Ringmaster's Secret"

When confused, sit back and try to arrange the facts into some kind of order. "The Ghost of Blackwood Hall

Don't release a runaway circus animal without some type of identification from the claimant. "The Mystery at the Moss-Covered Mansion

And of course,

Never sleuth on an empty stomach. "The Hidden Staircase"

That chapter wasn't quite as interesting, but the next one is a real doozy: "The Delicate Art of Etiquette."