Cinco de Mayo is next Wednesday. I am having a few friends over to celebrate what Wikipedia describes as "not 'an obligatory federal holiday' in Mexico, but rather a holiday that can be observed voluntarily. While Cinco de Mayo has limited significance nationwide in Mexico, the date is observed in the United States (also voluntarily) and other locations around the world as a celebration of Mexican heritage and pride." Sounds like a good reason to fire up the grill and start using that backyard that I moved to Atlanta for.
For now the menu is carne asada tacos (Trader Joe's has a great pre-marinated kind), DIY grilled quesadillas, Elote black beans, homemade pico di gallo and guacamole. Of course there will be Mexican beer and probably (if I have time) white sangria. Won't the sangria look great in these Ikea carafes and glasses? This is not a kid's birthday party, so use real dishes and flatware. No, "crystal" plastic flatware still counts as plastic.
For decorations, a few lanterns from Pier 1will increase the festive-ness. You don't have to spend a lot of money for a big impact. I also believe that your party decorations should not end up in the trash, so buy reusable supplies.