Take a non stick pan, heat it and sprinkle few drops of water to set the temeprature of tawa,pour a ladle full of batter and spread it well,put one spoon of oil around the edges and over the dosa.. Let it to cook for few minutes at low to medium heat till get light golden brown colour and crispness.Dosa is leaving the edges, wrap it on tawa (if you are cooking masala dosa then spread 2 tsp of potato mixture then wrap)