I would like to start documenting your systems of procedures so tasks are easily transferable to make your business sustainable. Capturing key nuances when you are not there to pass them in person, and key details to provide context for future decisions while creating business history. Confidently lighten your load, transfer duties, or deal with emergencies with less stress.
Writing down your company culture is important as well. Increasingly, customers want to give their money to companies they trust and align with morally.