Serums are staples in my regime. They give me shine and smoothness with no extraweight. My fav on dry hair is L'oreal Smooth Vive.
Otherwise, light moisturizers can also be good if you find the right brands...here are some I like in different price ranges.
Elasta QP Recovery (about $3-$4)
Frizz Ease Secret Weapon (roughly $6)
Phtyo 9. (about $18)
I find cone based products work well on oiler hair, because they don't add weight. Just make sure to clarify often - at least once a month.