You go through Sydney Thai consulate and apply online. Remember the visa starts the day it's issued so don't apply to soon or you eat into the 6 months valid time
Currently you can enter visa exempt for 60 days extend once only extra 30 days then zip across the border come back into Thailand and do same again that would give you 180 days. But the 60 could go back to 30 days entry stamp. MTV gives you the 60 days each time you enter plus 30 days extend is available each time as well
I go every month and have been doing so for more than 6 years (except through covid period) but started straight after covid again. On average I went 10 times a year 2 weeks each time.