Wash hair with a gentle shampoo and remove all product buildup
Let hair air-dry completely without applying leave-in products
Place a few clean, dry strands in a bowl of room-temperature water
Observe whether the strands float, sink slowly, or sink quickly
Check how long hair takes to get fully wet in the shower
Check how long hair takes to dry after washing
Spray a small section of dry hair with water and watch how fast it absorbs
Slide fingers up a strand from ends to roots to feel for roughness or smoothness
Compare how hair responds to moisturizers and oils over time
Repeat tests on multiple sections of hair for consistency