I currently use a 3:2 ratio of organic cocoa powder and cornflour, recently adding some eucalyptus essential oil to the mix! All you need to do is thoroughly mix the ingredients and store in a suitable container - I find a lockable sifter pot is excellent; you can purchase these online or recycle one like I've done with an old Lily Lolo foundation pot. Depending on your hair colour, you may find you need more or less of one powder - if you have a very light hair colour, cornflour/arrowroot on its own will also work.
To use, I sift some powder into the lid of my container and, using an old powder make-up brush, carefully dab some powder onto the brush, tapping off the excess and applying directly to my roots and massaging it in with the powder brush. Once finished with the powder, I brush my hair to ensure the powder has been evenly distributed. I currently wash my hair every other day and using this dry shampoo keeps it looking fresh on the no-wash days. Depending on your hair type, you may find you can get away without washing your hair for longer!
Do you use dry shampoo in your haircare routine?