I recommend the Daiso eyeshadow brush.

It is called the Daiso Eyeliner & Eyeshadow Brush. It costs 1,500 won and includes both an eyeshadow brush and a point brush. 1,500 won for two brushes is a really good price! The point brush is great for applying eyeliner and for the outer corner of the eye. It offers better value for money than other brushes, so I buy it frequently. I recommend everyone give it a try.