Thanks, that's pretty much how I would make a cocktail sauce too. That's the dark red one, isn't it? I also make Thousand Islad dressing by eyeballing the ingredients, the way my mum did.The 1000 island is from Kraft. Craig used purchased Marie's Ranch dressing for his vegetables. I've been known to use celery and carrot sticks with dressing for a snack, sometimes mushrooms and lightly steamed broccoli, using salad dressing for a dip.
Our cocktail sauce for shrimp is
About 1/3 cup ketchup
3-4 Tbsp prepared horseradish
Juice of half a lime more or less
1/2 to 1 Tbsp Worchestershire
Honestly, I eyeball everything so I'm guessing on amounts. The amount of ketchup is probably what I started with, but the rest is a guess because I make the mix first, then taste and adjust, generally adding a little more of the last 3 until I get the taste I want.