Initial Planning
It's best to start planning from the DC side of the system. That means the number and configuration of the solar panels and the battery bank type and capacity, if applicable. Battery capacity needs to loosely match the average solar production so that a good ratio of solar energy/battery capacity is provided. The aim should be that there is sufficient solar energy to recharge the battery bank most days, assuming average daylight conditions. An underpowered solar array means that the batteries aren't being adequately charged, and you'll be more reliant on the grid. A small battery bank may not provide enough capacity to power your evening requirements or a realistic backup function when the grid fails.
The solar array needs to be matched to the inverter solar input MPPT ports (hybrids or grid-tie inverters) or solar charge/controller inputs (for use with an inverter/charger). In either case, these have maximum solar voltage and current levels to consider. The electrical and physical arrangement of panel wiring is important.
System Configuration
In New Zealand most installations are based around a hybrid inverter and either high voltage or low voltage battery bank. Whatever system you go with needs to have its operational parameters configured to suit your preferences. For example a hybrid inverter can be biased with a hierarchy of energy use settings, for instance charging battery as first priority then suppling household load after. All battery compatible inverters have settings for battery charging parameters according to type. In Australia it seems most systems are grid-tie installations without batteries, a legacy of the perceived high cost of batteries plus the false promise of the job being 'battery-ready'. It will incure more than the price of a set of batteries to bring this up to a storage system, best to do it at the outset.
Monitoring and Control
All inverters will come with an online monitoring and control function in addition to the local monitor units with the inverter. These can be a hard-wired connection to your home modem and/or a mobile phone app. You will be able to keep track of the system operation and so will your technical support people.
Commissioning, Warranty, Inspection & Safety Certificate
If there's a single issue you need to take extra care of with the installation, it's that the system is commissioned properly on completion. That includes checking that the system operates to specification. You can monitor and control the system and see the function in its various modes. The installer will organise an electrical inspection to follow and provide the necessary certification. I have experienced some sloppy commissioning to the point where one installer told me his job was to "get it wired up and get out of here asap!".
If your equipment supplier and installer are two different companies, you need to ensure all parties are on the same page with respect to who you call regarding warranty issues. There are quite of few suppliers who don't do installations, and this can lead to problems finding someone to install. Sometimes they will have a subcontracter electrician, sometimes not. Issues with dealing with two different companies can include the installer not being fully or even at all familiar with the equipment, and potential warranty issues.