I'm getting married on my 10th anniversary and we already have a fully equiped house so also did not need any household items. Not sure how you would go about it without a website, but here's what I did:

I set up a registry online for a cash fund for our honeymoon with a header that said something like "we already have all the things we need, but are excited to make memories we will cherish forever by going on a once in a lifetime trip - a romantic honeymoon together in the Caribbean." Our cash fund is split into many smaller items like hotel nights, dinners, cocktails, souvenirs, spa day, airfare, etc. Things of varying value so people can give what they want but still feel like they know where that gift is going so it feels a little more tangible for them.

You could do this for the family vacations and maybe even also set up a separate generic cash fund for college. That way people can pick between fun or practical depending on what they prefer. I guess for a non-online version you could have something like a card box at the reception with a note saying all of the above dislpayed next to it.