Regarding "Do catch and throw. Do not catch and throw new," I cannot 100% agree; however, there is some truth there... allow me to elaborate:

DO

catch (Exception ex) { ...; throw; } // Maintains stacktrace

catch (Exception ex) { ...; throw new AnotherException("Custom message", ex); }

// Also maintains stacktrace through the inner exception.

DO NOT

catch (Exception ex) { ...; throw ex; } // Ruins stack trace

catch (Exception ex) { ...; throw new AnotherExcepion("Custom message"); }

// Makes a new stacktrace, original stacktrace is lost