Avoiding a recession: How do you know when it's coming?

[Robert Ellis]

I've been involved in real estate in Columbus Ohio since 2014. Since then the market has only gotten better every year. The last recession came in 2007 and 2008 and it seems based on what I have heard that it happened pretty quickly. 

So given that, I'm wondering for those of you or any members who have been through at least one recession in the real estate market, how did you know it was coming? What did you do to make sure you were ready when it came? How did your buying change? Did you take less risk? 

We get a monthly update from our local board of realtors and obviously as inventory creeps up to me that's a sign that the market is changing but I don't think they have the reports for columbus since 2008 so I can't go back and look up some of the red flags that would have let someone know that. 

Any tell tale signs? Foreclosures increasing? Inventory increasing? Properties not selling? etc. Looking for a few high correlation things that we might keep our eye on in our local market.