Althea had excellent knowledge of things like molecules and chemical compounds. A lot of scents were based on carbon and vegetation, allowing her to control the particles to some degree.
It wasn't easy nor was it intuitive. When she was learning this technique, it was very much like trying to hold bubbles with your bare hands.
One of the ways she found to make things easier for her was to just have the pre-prepared 'fragrances' on hand. She could spread it out like mist, and use her wood skills to integrate it more to her own body, making it seem like it was naturally emanating from it.
In her space, there was a small shelf filled with these 'fragrances' though some of them were actually 'stenches'.
As for the overall effect, it was similar to the camouflage skill, but in terms of the olfactory sense. Combined with the visual camouflage, this would allow her to be one with forests.
