First step, make yourself a nice cup of tea. The tea is optional, but a cup of boiling water isn't, so you may as well use it to make tea with.
Fill the cup and sit a small bowl on top. This bowl is what you'll make the hair oil in.
Add about that much olive oil (roughly 2-3 tablespoons, but my little bowl very conveniently has a line in it as part of the pattern so I don't really measure)
Next, add about a teaspoon of coconut oil. If you're lucky enough to live somewhere that isn't blindingly hot, your coconut oil will be lovely and white and solid and easy to measure. Mine looks like this, though and that's alright too.
Coconut oil can be very expensive so if you don't have it or can't afford it, don't stress too badly. Personally I think grapeseed oil would be a good substitute, but you can do your own investigation.
Lastly, add 6-8 drops of this stuff:
(do not adjust your sets, blurry photo is blurry)
Tea tree oil. You can also use eucalyptus. If you don't have those or don't like them, peppermint or rosemary oil. This ingredient is optional, as it's the weird hippie-voodoo bit. This is a "warming" oil and it's included to stimulate the scalp and increase blood flow to the hair follicles, which may speed hair growth, but again I'm not sure. I include it because I like how it feels on my head.
Let the bowl sit on the cup for 5-10 minutes.
To use, make sure you completely detangle your hair, working from the bottom up to limit hair breakage.
Take off or cover up that nice shirt and flip your hair over the sink. Massage the oil into your scalp and the roots of your hair first, then the very ends, then the rest of the hair shaft. Cover your hair with a plastic cap, cling film or a hair scarf so you don't get oil on everything ever.
Leave the oil on your hair for at least an hour (I leave it in at least over night, sometimes the next day, but I totally rock hair scarves) and then wash it out. Try to wash it out with cold to warm water, not hot, and use conditioner in place of shampoo. The "conditioner as shampoo" thing works well and was recommended to me by a dermatologist. Conditioner is basically a mixture of oil and water, and so contains enough detergent to clean your hair in order to bind the oil and water.
Happy... ahh... hairing?