Choosing the right gears for hiking is a very important. Below are the basic equipments, gears for various season and various kind of hiking activities:

Common gears:
Hiking shoes
Socks
Backpack with waist belt (Day trip:25 -30 liters )
Map (1:20,000 or 1:25,000) - Survey and Mapping Office - Free Map
Compass
Whistle
Flash light
Mobile phone
First aid kit
Bread and fruits e.g. apple, orange etc - Gives you energy
Water (>1 liter/day) - Quenches yoru thirst and avoid heat strokes
Cap, umbrella and sunglasses- Protects you from the sun
Umberlla and raincoat- Protects you from the rain and shield you from the heat
Shock resistance walking sticks

By Seasons:
Spring (March - April)
Warm weather and fog are the common characteristics of Spring. Many people has gotten lost in thick fog. Therefore, carrying a compass, map and mobile phone will prove helpful when you can' t see the trail. Also carry an extra jacket as temperature may also drop dramatically. Many plants disperse their pollens in Spring. If you have an allergy problem, please take your medication before going on the trail. Wear long sleeves and long pants when you are walking in rural trail.
Summer (May - November)
In the Summer, Hong Kong is very hot and humid. Heat stroke is the most common problem. Heat stroke happens when your body temperature is too high. In order to prevent heat stroke, please carry a retractable umbrella with a reflecting surface or colour e.g. silver. Please bring plenty of water and a wet towel.
Autumn, Winter (November - February)
The best season for hiking is autumn, Common gears will do fine in most of the situation. Extra clothes are essential in winter as the weather can get very cold.

By Activities:
Stream
Please wear a pair of plastic soled shoes and bring ropes. Do not carry walking stick.
Cliff
Ropes
Sea, Water Caves
Please bring a water resistant bag, swimwear (of course) and lifevest.
Tough Trail / Bushes
Please bring a pair of gloves, cutter, long sleeve shirt and pants