At Pike Place Market's Pure Food Fish Market, longtime fishmongers like Walter Compare don't want customers to leave with any questions about what to do with their catch. "I like to educate people as much as I can," says Compare. He's been in the business for 43 years and sees it as a service industry. What can he teach you how to do at the sink in the back? Clean a still-whole fish like branzino or trout; fillet a flatfish without mangling its delicate flesh; pick out a good hunk of salmon; peel shrimp; clean squid; and shuck oysters and clams. Just don't wear flip-flops.—Jess Thomson Pike Place Market, 622-5765, www.freshseafood.com.