In the past we were taught toners are meant to be used after cleansing the skin to restore pH balance, and remove cleanser reminence. Over the years this has changed, here are a few new facts regarding the purpose of toning the skin.
NOT ALL TONERS ARE TREATED EQUALLY. You don't always need to tone the skin. professional cleansers are already pH balanced to the skin it is meant to treat so restoring pH balance with your toner is not necissary.
If you rinse your skin properly you will not need to use your toner to remove reminence
So why do we tone our skin?
I avoid saying 'depends' as much as possible, buuut, it depends on the skincare line your using and what skin condition is being treated. Mist toners are meant to hydrate the skin(and usually have a few more gentle benefits) so mist toning a few times a day even over your makeup(depending on what make up you use) refreshes and protects the skin.
Many toners for acneic skin conditions or oily skin types are not in mist form, and often contain ingredients that aid in cell turn over and oil absorption(like salicylic acid, or benzyl peroxide for instance). These types of toners should be applied similar to a serum, and are a stronger treatment for more severe skin conditions. As a skin therapist it is your job to stay up to date with the skincare line you use, and KNOW the ingredients in your acne/oily line.
In conclusion: toners are now being treated as a hydrating product, or as a serum. They aren't the essential step everyone needs, like it used to be taught. It all depends on the skin type but cleanse, exfoliate, moisturize are definately the first steps....