Hi Louie H,
Yes, the best way to get the attention of your debtor is usually to send a letter of demand. This basically states that you are demanding repayment of the loan, failing which you will bring legal proceedings. Much of the time, a letter of this nature will be sufficient to get payments coming in from the debtor, however if it doesn't you will have to proceed with filing a claim in the Magistrates Court. However the fact that you sent a letter of demand before instituting proceedings will be counted in your favour by the court as it demonstrates you gave the debtor opportunity to avert the proceedings. Letters of demand should be posted to the person's place of residence by registered mail. Keep all receipts to prove that you sent it, in case they don't reply. If you can send it by different means as well - such as email, fax, facebook etc to ensure it is brought to the debtor's attention.
If you receive no response and have to institute proceedings, see your local community legal centre for assistance in filing a claim.
Check out these similar posts that deal with the recovery of private personal loans:
NSW - Ex-boyfriend not Repaying Personal Loan | LawAnswers.com.au Legal Aid Forums
NSW - Personal Loan to Ex Boyfriend - Small Debt Claim? | LawAnswers.com.au Legal Aid Forums
And here is a template for a letter of demand from the Lawanswers website
Letter of Demand Template for Australia | LawAnswers.com.au Legal Aid Forums
Let us know if you have any questions.