First you have to prepare the material and tools for making the Teachers' Day Card,like paper,gluewater,scissors,color pens and so on.
Then,you can cut out the shape of a card from a bigger piece of board paper.you can choose the shape,rectangular for most of the case,the colour of card should be nice and pretty,you can draw a picture on it or put down your wishes on it.
To make it more beautiful,you can stick something to it.
After you have done all these,you can put the card into a envelop to give to your teacher.