With the reestablishment of lockdowns in Victoria, facemasks are becoming mandatory in Melbourne.
Relevant information can be found on the DHHS with mask instructions here.
My own mask patterns are available for free download here, while HKMask is a highly recommended resource with free patterns in various sizes, and McCall's also have simple printable from their website.
There is currently a shortage of elastic across the country. Personally I use ribbon or shoelaces to tie them around my head as I find this more comfortable than wearing it on the ears (which are already full of piercings and glasses). Some people are using stretch fabrics (such as cotton/spandex jersey, just cut up old T-shirts or leggings) which can be cut into thin strips and used as an alternative- this is also softer and more comfortable than elastic, especially for children and people with sensory processing issues. Hair ties are another option which has been suggested to use for the elastic.