You wash your hair last.
Shampooing and conditioning your hair should be among the first steps you take when you get in the shower. Some of the residue from these hair products can remain on your face, skin, and hair even after rinsing, so it makes sense to follow hair washing with the rest of your shower routine. Using a gentle soap or cleanser on your body and face will help ensure you scrub away any remnants of your shampoo and conditioner.