I had 1 year and half full time and 1 and 1/2 year casual experience before applying. Also possessed cer 3&4, Diploma as well.
My work mates have various experience... one has husband, cer3,4, dip and advance dip, 1&1/2 years casual.
another one was a single, only had a cer 3, and worked for 1 year casual before applying ... both of them got visa.