The fastest way to upgrade a backyard party is with stemware. These plastic Triangle goblets, $38.99 for six, by ZakDesigns, laprimashops.com, are hefty to the touch, light on the wallet. Going potluck? Invest in melamine trays and bowls, from $13, by ZakDesigns, and deliver them to your team of cooks the day before the wedding—your buffet will have a clean, cohesive look. After the party, you can divvy things up among a few family members—or keep it all and have picnic gear for a decade or two.