Skin Preparation - Shreya's allSkin Clinic We know you have carefully kept your new makeup products in your makeup bag as you are saving them for special occasion. But you should know that irrespective of your skin type, it can be unpredictable at times. Even the expensive makeup items can be a reason for skin allergy or reactions. Therefore, you must try all the skin products in advance to save you from any unwanted situation on the day itself. Also, if you’re going to try a New facial or a new face treatment, you should do it at least a fortnight before the D Day.