Tamarind should be sufficiently tangy. If you have “new” tamarind or one that is very light in colour, increase the quantity of tamarind.
The tamarind pulp should be thick but of pouring consistency. Do not make it too thin.
Rice should be cooked such that the grains separate. The rice should not be sticky or have excess water.
If you are cooking rice in a pressure cooker, you can also pressure cook the tamarind along with it in a separate bowl.
Pulihora tastes better if you fry the red chillies separately and crush them by hand before mixing in Pulihora.