I particularly enjoy using natural yoghurt as a drink with spicy meals. It can be called lussi or lassi (depending on what recipe book you read) but it is basically yoghurt diluted half and half with chilled milk and add salt and ground coriander or cumin with some crushed ice. I also make raitha by adding finely chopped cucumber, tomatoes, celery and peppers with a light sprinkle of cayenne pepper and maybe a touch of chopped fresh ginger. There's no rules - just add the ingredients you like!