We entertain ALOT. I would get so confused on who liked what that I started a notebook and put the person/family name at the top of one page and made little notes. Nothing major. For example. Loves bananas or drinks diet coke. Just little things that I can do so everyone feels more at home.
You don't need anything special just index cards or PC file or notebook. I also add birthdays or anniversaries just so I know if they are celebrating anything special while they happen to be here.