What can I do to make my hair smell nice?

No poo for 4 months and it's going great. My hair doesn't feel oily and there's no smell either. But that's kind of the "problem". I'm used to having hair that smells really nice and I miss it. Of course, having hair that smells like literally nothing is not a negative but I still wonder if there are products or ways to make your hair smell nice without resetting the whole no poo process.