Use fresh lemon juice rather than bottled for the brightest flavor. Rinse capers to control saltiness. Adjust the texture by dicing pickles and onions coarser or finer. Adjust Dijon mustard to taste. Make the sauce a day ahead for better flavor. Use a non-metal bowl to avoid metallic taste. Variations include adding fresh herbs, cayenne pepper, garlic, swapping mayonnaise with Greek yogurt, or adding honey for sweetness. Store leftovers in an airtight container in the refrigerator for up to one week; do not freeze.