The system is very easy to use, but the big issue is eth volatility to the downside and Maker's oracle, which should have been working but froze up.
When you open a vault the system will tell you at what price liquidation gets triggered, so you have time until then to either pay back some of the debt or deposit more collateral.
Defisaver.com has great tools for Maker vault management. a lot of vault owners that used Defisaver got saved on Black Thursday.
They even made a liquidation dashboard which makes it easy to do collateral liquidations if you're into that sort of thing. https://defiexplore.com/liquidations