Besides the tartan, another symbol of clan affiliation for its members is the bonnet badge, generally made of silver, or a silver colored base metal. A sprig of the plant associated with the clan could be worn behind the badge.
Clan chiefs wear their crest within a plain circlet with the clan motto, and display three eagle's feathers.The Badge, in heraldic terms:
Arms: Or, an eagle displayed Gules armed Sable surmounted on the breast of a galley of the First within a bordure of the Third charged with three cross crosslets fitchee Argent.
Crest: A dexter arm in armour erect, the hand holding a dagger in pale all Proper.
Motto: Fortiter (Boldly).
On Compartment: Per mare par terras (By sea and by land)
Supporters: (on a compartment entwined with an Escrol bearing the second Motto) Dexter, a bear pierced in the back with an arrow all Proper; sinister, an eagle Proper.
An interesting combination of the badge and the tartan, courtesy of Michael S. McAllister.