on a first-name basis (with someone)
good friends with someone
I am not on a first-name basis with my neighbor.
Precautions while using Shampoo
To some extent, the alkanolamides that make shampoos foam also make the formulations thicker. However, other materials are also used to increase the viscosity. For example, methylcellulose, derived from plant cellulose, is included in shampoos to make them thicker. Sodium chloride (salt) also can be used to increase shampoo thickness.