Choose a theme and collect decorations to match. Whether it’s a Thanksgiving family feast, a Hanukkah celebration or a Christmas cocktail bash, a theme can give your gathering extra energy and help guests get into the spirit. Keep an eye out for appropriate decorations and order any specialty items you can’t find around town.Print and mail invitations. If you’ll be sending paper invitations, now’s the time to start on them. Buy printable versions from a local stationer, pick up a fill-in-the-blank style or order custom invitations from an online retailer such as Tiny Prints, Paperstyle or Etsy. Whichever route you choose, mail them two to three weeks before the party so guests have ample time to plan and respond.