Be nice, think about hard problems for a long period of time, only speak up when you have something positive to contribute -- be labelled an underperforming academic and managed into obscurity.
A great example of this is Peter Higgs, who famously said that he'd be unemployed pretty quickly in the academia of 2013. [0]
[0]: https://www.theguardian.com/science/2013/dec/06/peter-higgs-...