Most of the advice I'd offer has been encapsulated in the OP.
The addition is that it is worth remembering that progression should be seen as an outcome and consequence of good DEVELOPMENT.
This means that 500 hrs in the logbook does not entitle one to a first twin - rather, what the CP and other decision makers expect is that the newbie generally keeps his mouth shut (unless to ask a question) and his eyes / ears open and listens to the advice being offered by any mentors in the organisation. Furthermore, it is important that the effort is made to APPLY the knowledge being passed on. Commercial flying is a lot different to CPL training in a flying school environment! Find the right mentor and you'll learn how to do it safely and well.