1 cup olive oil
10 drops of your favorite essential oil (try rose or lavender)
Mix the 2 oils. Let sit for at least 24 hours.
Apply a tablespoon of warm oil to freshly shampooed hair. Leave for 20 to 30 minutes. Rinse lightly.
(Also, I remember hearing once that mayonnaise was supposed to be a good conditioner, so if you're feeling adventurous you might take a cup of Nayonnaise or Veganaise (soy mayo) and apply as much as necessary to cover your hair, wrap your hair in plastic wrap for 30+ minutes, then wash. I have no idea how this would work out though!)