The Times Higher Education on ‘10 steps to PhD failure‘. Some of these are rather US-specific, especially concerning the advice on funding, but generally these are worth thinking about. On the issue of staying in the same place, I don’t think that’s as clear-cut as it’s implied here: I did my BSc and PhD at the same place, without an MA in-between, and I didn’t feel it disadvantaged me. 4, 6, 7 and 9 are especially worth taking seriously.