Experienced investors: What do you wish you did in 2008?

[Tim Nisly]

We're entering a whole new world with this recession. Likely new banking rules, new ways to make money, new ways to go broke! I'm watching the Coronavirus start to impact the markets, and I'm really curious how things will go from here. Banks went super-low interest rates, and now they're holding off on that, but money hasn't frozen yet. AirBnBs could be done for a long time, until tourism recovers. Restaurants/bars and hospitality could be decimated. We've never seen a hold on evictions in my lifetime, and we don't know how that'll effect rentals. 

Taking a more defensive business posture - stock up cash, reduce risk, be prepared to adjust holdings quickly - seems like a given. While this is an unprecedented event in modern history, what lessons do we have from 2008 and previous recessions/depressions that are relevant in the next year or so?