While he didn't say anything about sunscreen, James Watson offers some advice to today's postdocs. According to the Nature Jobs Blog, the main points Watson gave were to travel and to not do anything boring.
For his postdoc, Watson headed to the Cavendish Laboratory at the University of Cambridge, where he, Francis Crick, and their colleagues tackled the structure of DNA. "In general the best work at any given time is not being done in your own institution, it is in other places, so go to these other places and meet them," Watson says. "And if you meet them sometimes you can invite them to come and work in your place."
Further Watson says to avoid boring projects and instead to "do something as important as you can." He tells postdocs to tackle one of the big questions still unanswered in their field. Further he advises talking projects over with colleagues. "Most of my success wouldn’t have happened without the particular intellectual environment I was in," he adds. "Having someone as good as Francis Crick that I could talk to, I was very lucky."