In your daily routine address the main problems of combination skin: visible pores, which are often clogged, pimples and black heads.
Cleansing: Use a cleanser for combination/normal skin on the whole face, use a toner for deep cleansing of the oily part of the face.
Use a Pore Minimizer or Anti-Imperfection fluid on the oily T-Zone to prevent break outs.
Apply moisturizer marked for combination skin or non-oily fluid (that is always lighter than “cream”) to the whole face. If your skin in the T-Zone is very oily and on the sides of the face and cheeks very dry use 2 types of moisturizers: one light and oil free for the T-Zone and the second more rich for normal/dry skin on the rest of the face. It is best if your moisturizer has UV protection and anti-oxidants.
If your moisturizer does not have UV protection apply Sun Screen. Very often the higher SPF in a sun screen the denser and oilier the consistency. That is why you should choose your moisturizer very carefully and ideally look for a Fluid with UV protection marked for combination/oily skin.
Check out Estee Lauder moisturizers with UV protection.