I have a lot of natural volume, because my hair is so dense, but I have good volume with conditioner-only styling. My hair is like a short, thick mane of curls....
It definitely depends on the conditioner you use though. I've used both TNNM and KCKT, and the former needs the exact amount or else it gets crunchy and weighed down (though conversely, too little delivers an insane amount of frizz), but Knot Today has been wonderful.