Make sure you give the curry paste time to develop its flavours, ie be sure to pan fry it for 2-5 minutes as this intensifies the curry's flavour.
Use a good quality coconut cream, you want it to be thick when it pours out of the can
Don't let the curry boil on a high heat, you just want a gentle simmer, otherwise, the coconut cream can lose its thickness and your curry will be thin and runny.
This is a rich curry, be sure to serve it with plenty of vegetables on the side to lighten it up, green beans, roasted cauliflower, cucumber sticks are all nice