If business owners ever do their own taxes, what are some key things to remember?
This is a very broad question and the answer all depends on what type of structure the business operates.
There are different tax rules that apply to sole traders, companies and trusts etc.
Also there are endless scenarios that would probably have to be taken into account.
My recommendation would be to always engage a tax agent/accountant. I have seen far too many cases where business owners have tried to save on accounting fees and done their own compliance work, only to find themselves in a much worse off situation.