Place the middle of the lei over your shoulders. Allow it to hang down both in the front and in the back. Do wear it pulled forward like a necklace.
Accept a lei if one is offered to you. The lei is a sign of friendship, and refusing the gift is seen as disrespectful of the gift giver.
Leave the lei on your neck as long as you are in the company of your host. Removing it while still at a gathering or in the presence of the one who gave it to you is considered rude.