These are some essential oil combinations that I've come across in bath products that I've liked.

Peppermint
Patchouli
Sage

Eucalyptus
Spearmint


The peppermint, patchouli, and sage combination seems like it would go really well with some sandalwood, or just a little bit of camphor.


Some of these traditional essential oil combinations could hold a lot of potential for fragrances.

These fragrances could be based on essential oils and then that would be something to branch off of, add a few synthetic nuances.

Virginia cedar and black pepper EO combine together to give a peppery oriental incense wood