How to identify suitable skincare product for a combination skin?

Find the right doc. I feel strongly about this topic, because unfortunately there are too many pros that fall victim to the same hype that the general public does. Find someone who truly believes in good scientifically- based skin care that can truly make a difference, not the newest fad. If they can't explain it to you in terms that make sense, move on. There is no substitute for good medicine, especially in skin.
Multiple products. "combination skin" refer to having both oily and dry skin typically onthe face and neck. There is rarely a simple solution and you may need to use different products of each area.