Only apply conditioner to the mid-lengths and ends of the hair extensions. Never apply conditioner on the bonds, as this will cause them to soften. Draw your hair to the back of your neck as if you were about to tie your hair into a ponytail. Hold the hair in one hand, and stroke the conditioner down the hair with the other. Leave on for a few minutes, rinse, and then gently squeeze to remove excess water.
Since the hair extensions do not receive nutrients from your natural scalp oils, it is important to keep them well moisturised by using a good quality moisturising conditioner. You may also apply treatments to the extensions, but make sure you avoid contact with the bonds.