Always use freshly squeezed key lime juice rather than bottled—the bright, authentic flavor is essential to an exceptional pie, and bottled versions lack the complexity and tartness that defines this classic.

Bake the buttered graham cracker crust at 350°F for 8-10 minutes before adding the filling to eliminate excess moisture and create a crispy, structurally sound base that won't become soggy.

Bring sweetened condensed milk and egg yolks to room temperature before mixing to ensure a silky, lump-free filling without overmixing, which can incorporate unwanted air bubbles.

Harvest lime zest before cutting and juicing the fruit—it's much easier to zest whole limes and captures more of the aromatic oils that add sophistication to the filling.

Refrigerate the pie for at least 4 hours (preferably overnight) at a consistent temperature rather than using a freezer, which allows the filling to set evenly and develop its ideal creamy consistency.