Ask HN: Accounting for Self-Employed/Contractors

For those of you working for yourself in a self-employed/contracting capacity how are you managing your accounts?

Are you using something like Xero or an alternative? Do you have a completely seperate set of bank accounts or do you just have a side account off your main personal banking account?

Any suggestions you may have on managing the communications side of things would be interesting as well. Do you keep a seperate email address or even mobile number for "business" communications keeping everything seperate from your personal communication accounts?

I am located in New Zealand for what it's worth but I think a lot of this could be universal.

Thank you in advance.