These amounts are very loosey-goosey. I don't measure, just stir up to taste in a plastic cup.
1 1/4 cups mayonnaise
1/4 cup Dijon mustard or 1 tsp. dry mustard
1 Tbsp paprika
1 tsp Cajun seasoning
2 tsp horseradish sauce
1 tsp pickle relish (or pickle juice if you'd like smooth sauce)
Tabasco sauce to taste (I only use a dash but you can add up to a tsp)
1 tsp garlic powder
Mix all ingredients together. Serve immediately with seafood or chill before serving.