I self manage a property in Melbourne from Perth. The only real issue I have had in the 6+ years I have owned the property was the first tenant trashing the place. First tenant was recommended to me by the selling agent who vouched for her as a 'close personal friend'. Turns out she was a ex property manager and thought she could set me up to get her bond back despite some minor damage to the property. I was very comfortable with taking her to the tribunal and got half the bond back. I have had no issues with tenants since.
You will need to read up on the rules before you start. There are guides for landlords on the relevant department's web site.
In Vic, we need to set up a property condition report at start and end, there are rules for rent reviews and increasing rent, and rules for the end of the property. There are a number of other rules, such as access, that you will need to be aware of.
You will need to conduct regular inspections. Don't assume you have a good tenant and that you don't need to do them. Also, if the tenant breaches the contract you should issue a breach notice in accordance with the rules in your state. I have had the situation where I had a "nice" tenant, who was generally maintaining a property well but did have some minor breaches. I handled them in writing instead of issuing breach notices. The tenancy ended badly and the tribunal was not impressed by my lack of breach notices (Perth). I imagine this would vary from state to state.
The biggest issue for me is finding new tenants because I don't want to conduct open houses and don't have access to the tenant database. I use an agent to find a tenant (with my final say), set up the lease including special conditions, prepare the property condition report and lodge the bond.
I mange the tenant after that including: regular inspections, issuing breach notices, arranging repairs and maintenance, regular rent reviews, final inspections for leaving tenants, return of bond or action at tribunal. I currently self manage two properties (three in the past) and I don't find that it takes a lot of times. A couple of my tenants were specifically looking for self managed properties due to problems they had with previous agent managed properties. They were my good tenants too!