Body tiaras are made by combining a body talisman with a tiara. In order to combine it with a talisman, simply use the tiara on the body altar with a body talisman in your inventory. Doing so earns you 37.5 Runecrafting experience. The tiara offers no combat bonuses.
A body tiara can be worn in the head slot, allowing the player to left click on the altar to get inside, as well as saving an inventory space.
The Body tiara can be used on the wicked hood, giving the hood two free teleports to the body altar, and 100 free body runes every day. This will consume the tiara.