It is important to cleanse oily skin twice a day, in the morning and evening, to remove impurities that can clog pores and cause spots or blackheads to appear. Avoid soap and alcohol, which aggravate the skin and can promote sebum production. Opt for gentle products and non-greasy gel textures for a mattifying result. Exfoliating once or twice a week will also help to remove dead skin cells that can contribute to blocked pores.