Ensure the milk is heated to the right temperature (around 40-45°C or 104-113°F) before adding the culture. Too high or too low temperatures can affect curd formation.
Use a small amount of fresh, good-quality curd (around 1-2 tablespoons per litre of milk) as a starter culture. Ensure the curd used as a starter is thick and creamy to encourage thick curd formation
Once you've added the starter culture to the milk, avoid stirring excessively. Stirring can disrupt the curd-setting process and result in thinner curd.
Some people find that curd set in clay pots tends to be thicker and creamier. If available, try using a clean, porous clay pot for fermenting the milk.