1) Australian driving licence for proof of current address.
2) Photo of Passport
3) Bank statement. I showed them 6 months of account history since mine was only 2 pages long but I think it's fine just to show 1 page with more than the 500,000 baht equivalent total.
4) Muay Thai Documents all supplied by Phuket King Muay Thai. It was 23 pages in total. I had to merge them all into 1 PDF and compress the file under the 3mb limit.
I applied at the Sydney Thai Consulate on March 20th Thursday night and was approved on March 23rd Sunday morning. So it only took 1 full business day for approval. I applied using a 6 month Muay Thai course in Phuket that cost 15,000 baht.
The application process was very easy and fast. If you want any info on what documents I used I can let you know