Jacqueline Kennedy

What would Jackie do: The dinner party has come a long way since her formal, elegant days. (Mark Shaw/Photo Researchers)

Then: Written and mailed, with RSVP deadlines.
Now: Emailed or texted. What's an RSVP?

Response to guest's "May I bring something?" query
Then: No, thank you, dear.
Now: Heck, yeah.

Host's hero
Then: Jackie Kennedy.
Now: Ina Garten.

The food
Then: Elaborate, multicourse.
Now: Simple, make as much as possible ahead of time.

Then: Formal, designed to impress.
Now: The centerpiece is whatever your garden yields today.

Dress code
Then: Suits and ties for the men, dresses and heels for women.
Now: Whatever.

Then: China, silver and crystal.
Now: Shabby-chic, mix and match — anything goes, as long as it can go in the dishwasher afterward.

The guests
Then: People you want to impress, like the boss and his wife. (Think Darrin and Samantha Stephens hosting the Tates)
Now: Your friends.

Then: Ironed and starched.
Now: Get real.