It depends which language I am using. If I am writing JavaScript I start the curly brace on the same line. If I am writing C#, Visual Studio tries to auto-format the curly brace on the next line.
Most places you work you will find there is a coding style that developer use. It can be loose or strict. I have always tried to conform to what everyone else does unless they are doing something stupid.
The most important thing is to try to format the code so it is as readable as possible so the next developer can easily read your code. 80% of development is maintaining code someone else wrote.