The following is advice I have received, as well as advice I wish I had received.
Value in the business. There should be a clear benefit for consumers leading to building of genuine value. Otherwise the company will last as long as the marketing monies last or the highenergy environment doesn't end. Focus, focus, focus. Stick to your knitting.
Conserve capital. Cash is king, and the only thing that matters at the end of the day.
Eliminate all nice-to-have costs. Introduce measures that may be considered harsh in normal times, but are needed for surviving in uncertain and volatile times.
Keep the team motivated. As they see the dark clouds they need reassurance that the world will not fall apart. Be transparent with the team. Keeping people in the loop allows them to take mature decisions. I have rarely seen people abuse this trust and it brings in a huge amount of ownership.
Calculated risk. Take risks, but only calculated ones that are backed by data, not just perceptions Keep close tabs on customers. It helps to get early signs of any trend, positive or negative.
Long-term perspective. One needs to have patience to weather out storms, and storms don't last.