It has come to my attention that the composition of the ideal Tartar sauce recipe is not widely known. I will attempt to remedy this.
The ideal Tartar sauce recipe has many ingredients, and so it's not for the lazy or unprepared cook. Its benefit is that it's delicious. Let's list the ingredients:
Mayonnaise, chopped pickle, minced onion or onion powder, minced garlic or garlic powder, mustard, horseradish, lemon juice, salt, black pepper, Worcestershire sauce, and Tabasco sauce.
The skilled cook will need only this list, the proportions will be intuitive with some adjustments to one's predilection. For the inexperienced, I can only offer some easy to find recipes found on the internet, and begin adding any ingredients listed above, with these caveats:
Go easy on the mustard. If you plan to make one cup of Tartar sauce (too much, usually, for a small group - a half cup should serve 4 easily) but for one cup, two heaping teaspoons of dark mustard preparation is sufficient, or one teaspoon of dry mustard powder. Garlic: go easy, one fat clove for this cupful. Worcestershire: one teaspoon. Juice of one fat lemon. One teaspoon of Tabasco sauce. It is important to use Tabasco because it is infused with the flavor of the oak barrels it is aged in. Black pepper: a teaspoon. Horseradish: I like a lot; a rounded tablespoon of pure mashed horseradish. Pickle, one small to medium pickle chopped: 3" long, 1" thick would be about right; perhaps more. Onion: half a small onion (2") chopped.