They are usually most popular with high income earners and people in the later stages of their working careers who are keen to build their retirement savings.

Young people may think they have other priorities like raising children and paying off the mortgage.

Super is tied up for the long term, but even small contributions can earn valuable tax refunds now and provide a large benefit at retirement time.

Employers must pay 9.5 per cent super contributions on salaries.

For a person earning $80,000 per annum that is $7,600 of contributions.

Each person can put in up to $25,000 of tax-deductible contributions annually.

That includes the employer amounts.

Therefore the $80,000 person could put in up to $17,400 more if they really wished.

If they could make that contribution, it would be tax deductible and potentially earn them a $6,000 tax refund.

Now that would be useful.

Contributions to super can be made as a one-off lump sum.

They must be in the super fund by June 30 to qualify for the deduction.

Most funds have instructions on their websites to facilitate this.

Some of the contributed amount will come back as a cash refund once the tax return is submitted.

With interest rates extremely low, super funds are likely to earn much better returns than cash in the bank.

The tax on the earnings inside the fund is also lower than personal marginal rates, meaning higher returns.

The long-term benefit is an improvement in one's retirement living standard.

There are other less painful ways to get extra into super and gain the benefits, such as a regular monthly contribution over the whole year.

An automatic deduction from a personal bank account will hardly be missed. We quickly get used to having a little less to spend.

Contributions can also be by salary sacrifice, a deduction from pre-tax pay each payday.

For example, the person wanting to put in $17,400 could request a pre-tax salary sacrifice super payment of $334 per week.

That would reduce their after-tax take-home pay by a more affordable $219 per week.

Of course, smaller contributions are also a valuable strategy.

People who haven't been salary sacrificing so far this year could consider sacrificing all their salary for the remainder of the financial year.

If they have reserves or a partner earning enough to pay the bills this may be a smart option.

Another way to get extra into super is to sacrifice overtime payments or bonuses.

Based on typical past fund returns a sacrifice of $100 per week for 20 years should add around $180,000 to a person's retirement benefit.

Do it for 30 years and the super account should be about $420,000 more.