Giles is an experienced and accomplished advocate who has developed a strong practice in criminal and matrimonial trials.  His criminal practice ranges from commercially oriented crimes such as corruption, fraud and Securities and Futures Comission matters, to violent crimes, dangerous drugs and sexual offences.  Giles was the Chairman of the Hong Kong Bar Association Special Committee on Criminal Law for 2 years (2005-2006) and currently remains a member of that committee.
Giles' matrimonial practice involves all types of contested matters, such as custody, ancillary relief, domestic injunctions and inheritance (provision for family and dependents).  He is also a qualified and accredited general and specialist family mediator.

In his regulatory practice, Giles deals with matters brought against the construction industry (health & safety, environment and other compliance issues) and the food & beverage sector (health & safety, compliance & licensing).

Giles is also very active in conducting seminars for fellow professionals.  He regularly delivers talks for both the Hong Kong Bar Advanced Legal Education and the Law Society of Hong Kong.  For the past 10 years Giles has taught students and junior barristers criminal and civil advocacy alongside visiting delegations and individuals from the National Institute for Trial Advocacy (NITA), the Australian Advocacy Institute and teams from the Inns of Court, London.  Giles is a founding director of the Hong Kong Advocacy Training Council (HKATC), and has taught advoacy to prosecutors in Brunei and Fiji, and to English Barristers at Keeble College Oxford.