The usage methods and techniques of a compass mainly include the following steps:

1、 Preparation stage
Select location:
To prevent indoor magnetic field interference, it is preferred to use a compass for measurement outdoors.
If it must be used indoors, try to choose items that may cause magnetic field interference, such as electrical appliances and iron objects, or place the compass on wooden stools, tables, or even rice bowls for measurement to reduce errors.
Understand the structure of a compass:
The main components of a compass include Tianchi (compass), Tianxin Shidao (red cross nylon rope on the outer disk), Inner disk (copper plate disk engraved with a circle of black background and gold letters, the entire disk can rotate back and forth, and traditionally one circle is called a layer. One layer is the direction of the twenty-four mountains), Outer disk (base), etc.

2、 Basic usage steps
Posture and grip:
Hold the compass with both hands on the left and right, slightly spread your feet apart, and place the compass between your chest and abdomen, keeping it horizontal. Do not raise it high on the left or low on the right, or high in the front and low in the back.
Adjust the cross fishing line:
Adjust the cross fish thread above the compass, keeping it perpendicular and parallel to the measuring object (such as the door of a house) to ensure measurement accuracy.
Rotate the inner disc:
Rotate the inner disc with the thumbs of both hands, and when the inner disc rotates, the Tianchi (i.e. compass) will also rotate accordingly.
Keep rotating the inner disk until the magnetic needle in Tianchi stops and overlaps with the red line in Tianchi. At this point, the direction indicated by the magnetic needle arrow is south, while the other end points north.
Determine the direction:
Determine the orientation of the measurement object based on the direction indicated by the magnetic needle and the scale or characters on the compass. For example, when measuring the orientation of a house, the person standing inside the house facing the direction of the door is taken as the standard, with the back as the seat and the face as the orientation.
Record results:
Record the measured orientation information for subsequent analysis or application.

3、 Precautions and Techniques
Avoid magnetic field interference:
When using a compass, efforts should be made to avoid magnetic field interference sources in the surrounding environment, such as electrical appliances, ironware, etc.
Maintain level:
When using a compass, it should always be kept level to ensure the accuracy of the measurement results.
Calibrate compass:
Calibration should be performed before each use of the compass to ensure its accuracy and reliability.
Observe pointer stability:
During the measurement process, attention should be paid to observing the stability of the magnetic needle. If the magnetic needle cannot stabilize after long-term shaking, it indicates that there is a significant problem with the magnetic field in the area. At this time, a new measurement location should be selected or other measures should be taken for calibration.
Tips for measuring houses:
When measuring, it is recommended to face the door of the house and look inside as indicated by the arrow, in order to adjust the compass to be parallel to the house, and then start rotating the inner disk to calibrate the magnetic needle.
The direction indicated by the arrow on the compass is south, and the other end points north. If the compass pointer points to the south and basically matches the actual direction (with a deviation of 3-4 degrees from left to right), it indicates that the magnetic field here is relatively stable and there is no major problem with feng shui.

By following the above steps and techniques, one can accurately use a compass for azimuth measurement and feng shui analysis. At the same time, patience and attention to detail are also required when using a compass to ensure the accuracy of measurement results.