So, I've been making my own deodorant for almost a year now and love it.
Amazing. Works better than the stuff I'd been buying, easy to make, leaves no marks on clothing, lasts ages (made my third batch last month) and contains no nasty chemicals. Won't go back to commercially produced deodorant.
Melt 2 tablespoons of coconut oil in a dish, mix in 2 tablespoons of arrowroot powder, 2 tablespoons of bicarbonate of soda and a few drops of tea tree oil. Pour into a jar. Done.
There are a few minor downsides:
Do give it some time to start working - the site I got my recipe from warned of an acclimatisation period of up to two weeks.
It can sting a bit if applied right after shaving.
Scooping it out of the jar with a finger and applying it by hand takes some getting used to.
In warmer weather it reverts back to its melted form - batch #2 went into an old deo stick container and spent the summer in the fridge.
Other than that, bloody brilliant stuff.