If you intend to make a Security for costs application, you need to be able to put a report in support of it to the Court. This report needs to be prepared by an experienced Costs lawyer.
The report is based on costs already incurred prior to the Security for costs application, such as costs of the application and an estimate of reasonable costs to be incurred in the future using a pattern of costs to date, costs incurred in previous proceeding, and estimation of counsel fees.
(e.g. Costs of an Appeal could be calculated using a pattern of conduct of other party during primary proceeding)