Combine all ingredients in a bowl and mix until well blended and smooth.
Can be used immediately, but is best after a couple hours in the refrigerator.
Notes
If you like fresh herbs, try some fresh dill or fresh chives. Finely chop them and add just a pinch or two.
Use a good quality mayonnaise, or make your own.
Give the tartar sauce a taste and adjust as needed. If it's too salty, add a little more mayo or even some sour cream. If it needs more of something, then add it in small amounts. I don't think you'll need to tweak it much because it's darn good as it is!
Store tightly covered or in an airtight container in the refrigerator for up to two weeks. A mason jar is perfect. For best results and flavor, use it in one week.