First, look at the banner.
If you read from left to right, the first line should be on the left. If you read it from right to left, it should be on the right side.
Second, the distinction between the couplet's upper and lower lines should be based on the content of the couplet.
Couplets, in addition to the battle and other requirements, generally should be on the narrow down flat. The key to posting couplets is to look at the last word of the left and right couplets, if it is the oblique tone (on the sound and go, that is, Mandarin three, four), is the top of the couplet, but the flat sound (yinping and yangping, that is, Mandarin one, two) is the bottom of the couplet, and in addition to the need to combine with the couplet to determine the content, the general couplet is required to be narrowly flat.
Three, first determine the upper and lower couplets, and then determine the direction of posting.
Posting couplets when the first cross-checks on the top of the door, and then down according to the orientation of the cross-checks on the left and right couplets.