Personally, I am using Aloe Vera. And it's no problem for me because we have it as our household plant.
What I do is massage it throughout my scalp and leave it for 30 minutes or longer. I usually do it when I wake up in the morning, leave it there until I take a bath.
Occasionally, I am using coconut milk as well. Same think I do with the Aloe Vera, massage it on my scalp and through all my hairs and leave it for 30 minutes or longer. My wife, simply leave it for around 10 minutes, because she has to leave for work earlier than me.
Again, no problem for the coconut for us... It's either we can get from my brother's farm or simply buy one at the market.
The key is consistency, this won't get results overnight or a month. Do it always, you can do it everyday or every other day.
Olive oil, I think is also a good one, but I haven't tried it. I'm happy with the Aloe Vera-Coconut Milk Combo.
I have also read a few here, but haven't tried their recipes;