Single employee pay run

I am now the only employee in the business.  I work for a self employed mechanic who did employee a tradesman but that tradesmen left last week, leaving me as the only employee.  I work as a casual btw.

My question is this.  If I don't work every week - occasionally there isn't enough work for me so I leave it until the next week or so.  Should I still be doing weekly payruns but for the week I don't work do the pay run as a zero hours/zero $$ pay?  Or do I just do a pay run when I do work - meaning there could be a week or two between pay runs maybe a few times during the year.  

I am new to MYOB and am used to Xero where you could simply select a pay run.  MYOB seems to work a bit different.  

If it's correct to do the zero hours/zero $$ pay run I would prefer to do this.  My only concern is how the ATO will react to $0 pay runs being done.