For those planning to pursue permanent residency and citizenship, my timeline below.
Requirements and legislation might have changed or potentially will change, but hopefully it provides some insight.
10&13 Oct 2012 - IELTS
26 Oct 2012 - IELTS Results
17 Feb 2013 - Lodged Visa 476
07 June 2013 - CO Allocated
22 Aug 2013 - Visa Grant for me and my girlfriend
07 April 2014 - Touchdown Melbourne!
14 March 2015 - IELTS in Melbourne
16 June 2015 - Submitted EA Skills Assessment (Electrical Engineer)
23 June 2015 - PTE-A in Melbourne
2 July 2015 - Received positive EA skills assessment
6 July 2015 - Submitted EOI for visa 189 (65 points)
3 Aug 2015 - ITA
4 Aug 2015 - Lodged app for visa 189. Bridging visa released
19 Nov 2015 - Visa 189 granted for me and my GF
7 April 2018 - Lodged Citizenship
21 Jan 2019 - Immi response
29 March 2019 - Citizenship exam passed. Now waiting for the ceremony