in a large bowl, add wheat flour. there should not be any lumps in the wheat flour. add 1 cup of water. mix it well to make smooth paste. now add cumin seeds and salt. mix well. add water if required to make dosa batter consistency. keep aside for minimum of 5 minutes. heat the dosa pan. pour a ladleful of the batter at the centre of dosa pan and start making dosa in circular motion. sprinkle some oil over the edges. close and let it cook over steam.