Stick with the paradigm used within the environment you're coding.
An obvious example is using Pascal case for methods in .NET, camel case in Java.
Less obvious examples relate to using the same conventions as those used in the standard class library.
There's a lot to be said for this goal. Naming conventions convey a lot of information for humans, and very little for the compiler. Anyone who has consumed an API in one environment that uses the conventions of another environment has noticed how much the alien code stands out.
Consistency is a valuable characteristic that reduces cognitive load for a human consumer of code.