What I am trying to do with students is to give them guidelines to start writing an article as soon as possible when they start their PhD. Writing a paper makes them seeing the wider picture but it also guides them better into new experiments that they need to carry out. And the second thing that I always encourage them is to take part at the end of Year 1 of their PhDs at an international conference and present as a lecture (not as a poster!) their work. This experience makes them more confident in their work and confidence is a fundamental virtue in research.