The most common way for employees to add to their SMSF balances is to use the 10% (9.5% before 1 July 2021) compulsory Super contributions. Additionally, you can salary sacrifice Super into your SMSF.
Articles and advertisements explaining how you can make the most tax-effective use of your Super often refer to personal contributions or Super salary sacrifices. You can find more about these at the ATO website by clicking here.
Superannuation Warehouse also has a page explaining Self-Employed Contributions in an SMSF. Another option may be to add a non-concessional contribution (after-tax money) to your SMSF. The disadvantage of this is that you will have paid tax at a marginal rate (after tax money) and therefore lose the concessional tax advantage of contributing into the Super.
In order to advise your SMSF that you intend to claim a tax deduction for your personal super contributions, you should complete a “Section 290-170 notice” tax form. You can download a copy from this web page.