How to Wear a Lei

How to Give a Lei
A lei is traditionally presented to another person by placing it around their neck and giving them a kiss on the cheek. Some say a more traditional and respectful way to present a lei is for the giver to to bow slightly and raise the lei in front of themselves, at about heart level, letting the other person take the lei and place it around their own neck. In modern times it is more common for the giver to place the lei around the recipient's neck along with a kiss. Note that it is considered bad luck to wear a lei you plan to give to someone else or for a pregnant woman to wear a closed a lei. Any lei can be made open and pregnant women should always wear an open lei.

How to Receive a Lei
It is disrespectful to decline a lei if one is offered to you. If you are allergic to any of the lei materials, or if you are not in a position to wear a lei that is presented (for example if you are playing amusical instrument) the lei should be put in a place of honor to show respect for the giver. A lei can be worn for any occasion or no occasion and it is fine for you to purchase your own lei.

How to Wear a Lei
A closed lei should be worn on the shoulders with half of it hanging in the front and half hanging in the back. It is fine to wear more then one lei at a time. Graduating scholars often wear so many lei they can hardly see above them."
Found on: http://www.hawaiiforvisitors.com/about/lei-etiquette.htm