[Image: http://wiki.mabinogiworld.com/images/thumb/5/5c/Tailoring_game.png/200px-Tailoring_game.png]
The picture above is the minigame that is initiated when finishing a piece of clothing while tailoring. You have approximately a quarter of a minute to finish.
In order to obtain maximum quality, you have to match each circle to each marker in succession by clicking and dragging each thread to it's counterpart on the opposite side of the cloth or fabric.
[Image: http://i.imgur.com/d8R681O.png]
in order to obtain maximum quality (without bonuses such as weather, reforges, or production parties etc) practically, you will have to match the needle on the right to each X and O accordingly to the center-most pixel.
The Diamond-shaped end on the needle is about 5 pixels up, down, left and right. The pixel in the center must match up with the center most pixel on each X and O accordingly to obtain the highest quality. Missing even a single pixel could mean the difference between "A" and "B" quality productions since the quality is measured by the accuracy and completion of the mini game itself.
It may sound easy at first glance, however if you have a sensitive mouse, it becomes quite difficult to accomplish.
This method can also be used with smithing as well when matching the diamond cursor on the hammer with each pinpoint on the minigame.
In order to prevent your creations from going full potato after running out of time (which you have little of when you try to focus on perfecting your work) you can just press the closing button on the minigame at the cost of the finishing items you use in the finish menu. (You might need to buy alot of finishing materials while you're at it.)
Credits go to Indexu who contributed quite a bit on the subject a long while ago, I just digged up the info and reposted because it wasn't really easy to find.