Take green chillies chopp finely or crush,ginger chopp,curry leaves,coriander leaves chopped.
Dry tost cumin seeds and with roallingpin make powder.
In blender add curd water blend pour in a bowl add salt as per taste mix well then add green chillies,ginger,curry,coriander leaves chopped mix well. this is south indian butter milk.
North indian butter milk,take a glass add cumin powder,chat masala,add butter milk mix well then top it of with some more cumin powder.