Hello, I recommend you to study the basics of mixing here.
มือใหม่กรุณาอ่านที่นี่ Combination/oily skin Choose ingredients that help balance oiliness in the section
ลดความมันผิว , brighten skin tone Select the ingredients in the category.
whitening Yes, I have a rash, please check the cause/factor that provokes the occurrence of rash. You may be able to choose a combination of ingredients.
ลดการระคายเคือง , which is effective only in case of skin irritation. But should check the cause and stop the cause as well, ingredients that help nourish the skin. can also be used together in the formula to strengthen the skin and reduce the likelihood of prickly heat