Fill two large glass jars with green, gold and purple Mardi Gras beads. Place the beads inside the jar in no particular order, or create three layers of color with the beads. Place one jar on each end of the mantle.
Warm up your hot glue gun and place a glue stick inside it. Glue green, gold and purple feathers onto a foam wreath until the wreath is completely covered. Place the feathers so they are all facing the same direction for a cohesive look. Glue a small Mardi Gras mask to the wreath to complete the look. Hang the wreath just above the center of the mantle.
Scatter more Mardi Gras beads and feather boas along the length of the mantel. Prop Mardi Gras masks up on the mantle as well to complete the look.