When it comes to decorating the venue for your mehendi function, a vintage theme could work wonders for you. Install interesting looking cages around the venue and the lighten the mood of the entire place. Decorating the cages with a bunch of flowers will add an extra touch to the decor aesthetics.
An extremely Indian and earthly décor idea for your mehendi is the Kathputhali or Rajasthani puppets. These dolls can be hung in the doors and around the venue to give a the space a cheerful and vivid look.