For Mardi Gras make up some fun games to keep your guests entertained at the party. Since this is the last day before Lent, have everyone write something that can be given up for the period before Easter on a slip of paper and put it into a hat. Then have guests draw from the hat one by one to see what it is that they have to give up for Lent. You may find it necessary to look through the suggestions first to make sure no one wrote anything inappropriate on their slip of paper. Or if your party is for children you can write up some simpler suggestions of things to give up for Lent, like chocolate and chewing gum.
In other countries Fat Tuesday is known as Pancake Day. People celebrate by literally eating a lot of pancakes. You can try adding the breakfast food to your menu, especially if the party has kids. They'll love a mix your own pancake buffet. Set out the mix, and ingredients such as blueberries, chocolate chips, walnut and other items for kids to add to their pancake batter and then have an adult fry them up. This can be a great way to celebrate if you want to have a party early in the day.
Decorate your party in the traditional colors of purple, gold and green with streamers, confetti, balloons and other décor. Guests can all come wearing masks and people can spend the evening trying to figure out who is who. As a door prize give your guests beaded necklaces when they arrive and some clappers or noise makers to celebrate with. Set some Cajun style music in the background for guests to dance to, Blues or Zydeco style songs really adds to the party. With these ideas you can make your Mardi Gras a safe and memorable one for all of your guests.