<prompt> Human: Hello guys, how do you guys do that? My income can change a lot month to month, can be less than 1000 BRL up to 8000 BRL and Im having a bad time with this, how to properly plan in this case?  <response>: About one third of my income is a percentage of sales and my wifes income is entirely commission. We get some big variations month to month. What you need to do is save a buffer of money to insulate you from the month to month variations. Then spend at a number that is lower than your average monthly pay. If your buffer is big enough and your spending is less than you make on average, youll be ok. 