You can determine if you have an oily skin type by observing your skin after washing your face:

1. If your skin feels excessively greasy and shiny shortly after washing, especially in the T-zone (forehead, nose, and chin), you likely have oily skin.
2. Oily skin often has enlarged pores, which may be more noticeable, particularly on the nose.
3. Oily skin is prone to acne breakouts and blackheads due to the excess sebum production.
4. Makeup may have difficulty staying in place on oily skin, and you might notice it becoming shiny or sliding off throughout the day.