How to use trekking poles for outdoor hiking?

Correct posture - there are differences in the use of poles in different terrains:

Flat & Gentle Slopes: Keep your head up and your chest up, the tip of the stick is always behind your body, swing the stick alternately in opposite directions, do not turn along.
Steep Slopes: Double pole support can provide a more stable fulcrum and reduce the pressure on the knees. Especially when going downhill, the palm can be wrapped around the handle.
Crossing the river: The two sticks are used as support in front to move forward.
Reasonable use of stick rest and protective cover

The pole support is to prevent the trekking pole from being too deep in the soil and difficult to pull out or from being stuck in the rock crevice and twisting the pole. Generally, the softer and more unstable the road surface, the greater the need for a rod support with a larger force-bearing area.

The stick tip protector is used on hard roads; when walking on concrete or flat rocks, wearing the stick tip protector can prevent slipping, and protect the stick tip while avoiding people or things from being stabbed. When walking on soft roads, the protective cover should be removed.

The mud support is used on soft roads; when walking on soft roads such as sandy ground and grass, the sharp tip of the stick is easy to sink into the road, and it takes a lot of effort to pull it out; while walking on hard roads such as gravel roads, if there is no stick support, Trekking poles are prone to breakage when they get caught in the cracks of rocks, so don't take off the mud support easily.