How do you know if a product is breaking you out?

its the product that is what happened to me i tired so many tinted moisturizers to be honest and they all made little dents on my cheeks like they were pimples and i gave all mine away to someone and now i just stick to a every light foundation liquid and it works fine so. you have to the same problem *** me and it sucks because once you open the stuff you cant take it back that is why i needed up giving mine away. try a light foundation then a tinted moisturizer. the new cover girl natureluxe silk foundation is great its every light and it works better then the normal little drug store tinted moisturizers so.and i all so love the Neutrogena - Healthy Skin Liquid Makeup foundation every light wight *** well and it gives you a little glow so. both of those light wight foundations are really good then a tinted moisturizer.