First of all, you need to know the habits and customs, and you need to know the top and bottom of the doorway. The right hand side facing the door is the upper head and the left hand is the lower head.

2

The banner is the center or title of the couplet, which serves as the finishing touch. Judging from the direction of writing, if you write from right to left, the top couplet will be on the right, and vice versa on the left.

3

The next step is to distinguish between the couplets of the upper and lower couplets, one is based on the tone of the flat and narrow points. The spring couplet is about the level and oblique tone, the last word of the upper couplet is oblique tone, the last word of the lower couplet is flat tone. One tone and two tones are flat, and three tones and four tones are oblique.

4

Then the second is to distinguish between cause and effect: the cause is the first couplet, and the effect is the second couplet. Because where there is a cause before there is an effect after.

5

Distinguished by chronological order, the upper couplet is on the left, the lower couplet is on the right. There is a chronological order.