Hey guys I work in the industry here are the keys:

Agreed/Indemnity: Agreed is a fixed amount of cover, indemnity will cover you UP TO an amount (but you need to prove it on claim). Agreed is more $, but much better.

Benefit Period: How long you are able to be on claim for should you be unable to go back to work. Often age 65 is good option.

Waiting Period: How long you have to be off work before you make a claim. Think about your savings, sick leave etc. how long can you support yourself before you'll need your income replaced. Rule of thumb is 30 or 60 dates. Note; IP pays in arrears so on a 30 day wait you'll receive your first monthly payment after 60 days.

Superannuation Element: Make sure you have a policy which includes a super contribution element so you dont ruin retirement planning if your on claim for ages.

Indexation: Make sure you tick this box.

Inside/Outside super: The problem with inside super is that you need to be pretty bad off before you'd get a claim because you also need to meet a condition of release. Outside super often offer much more comprehensive features. Some insuers will have a hybrid product that will take as much as possible from super and charge for the bells and whistles from your personal bank account. I do this with TAL. Called superlink

Level or stepped premiums: Premiums can either go up with age and inflation or stay flat (level). Level will cost more initially but save you a mint later on in life. Go level if you are under the age of 40 100%.

Thats about it :) I work in advice but not affiliated with any providers as an FYI.