What is the use knowledge of coasters?

There is no formal and standard way to use coasters. The key is safety and practicality. However, coasters are sometimes used as a foil. For example, you need to add a coaster when drinking coffee, otherwise there will be no modern and elegant feeling. 

So what are the knowledge and points of attention when using coasters?
1. It is best to make coasters only. Coasters are used for multiple occasions and may not have that kind of fun;
2. Protection of the coaster No matter what kind of material the coaster is, it should not be bumped frequently;
3. Cleaning the coaster In addition to the paper coaster, the others can be washed with water or brushed.