I've always been one of those women who are wondering why we should use a toner after washing our face, isn't it pretty unnecessary? Not at all, let's see why.
Soaps and cleansers have basic formulas, while our skin's PH should be around 5.5, depending on the zones considered. If our face's skin was normal, it should be around 6.5. Instead dry skins have a more acid PH and oily skins have a more basic one. That's why with cosmetics (or simply a toner in this case) we might be able to balance our skin's PH.
Floral waters are obtained by steam distillation from aromatic plants, therefore they are a remarkable beauty friend. Their PH is generally 5 or 6, for this reason it is a good choice to use them as toners, even if I'd suggest to add a tiny drop of Acid Lactic if you have oily skin (in order to do this, you MUST have PH testers to check out the result because acid lactic is such a powerful substance).
At the moment I'm using a delightful rose water that I purchased from LaSaponaria. Rose Water is known for being an astringent and fighting against the ageing of the skin, plus it is so refreshing and smells divine! :)
MY FINAL ADVICE: you don't have to look for expensive toners, which will probably contain alcohol (for its atringent properties), just use floral waters and empower them with an essential oil of your choice, you'll let me know then!!