Services are often very crowded. IDP is recommended but not legally required. British passport holders intending to visit mainland China should obtain a visa for China before departure. Visa's are NOT available to British passport holders at the border, attempting to travel to the border without a visa may lead to detention at the border. Within Hong Kong the usual social courtesies should be applied.
Casual dress is acceptable.
Your Passport to Safer Travel gives practical tips and advice for travelling independently aroundthe world - safely.