The rule of thumb
Plan on four to six picks per guest for a two-hour evening with finger food, and add one per drink if you're garnishing cocktails. Twenty guests at a cocktail party works out to roughly 150 picks.
Match the length to the job
4.7-inch picks (pearl tops, knots, paddles and seasonal designs) reach the bottom of a martini glass and stand tall on a board. 2.5-inch picks (plain, frill and flag) are for single bites: canapés, sliders, cupcakes.
Pick a theme
Umbrellas for summer, flags for match day, pearls for weddings and anniversaries, pumpkins in October and Santas in December. One theme per table looks intentional; mix only if the colours agree.
Keep a plain stock
Whatever the theme, a bag of plain double-pointed toothpicks is the backstop. They're what we'd put in every kitchen drawer anyway.