black pepper eo is awesome - and - if it's very good, expensive. I use it in my chai tea eo blend lip balm. I like it for lips because it increases circulation, bringing blood to the lips with color, and is an aphrodiasic! 1 part is all that's needed to get a nice "pucker" and "plump" for my customers. I can't reveal my secret recipe, took forever to get it right - not to mention incredibly expensive, but everyone has their own anyway. My suggestion if anyone were to attempt a chai blend - use fo samples first (found out the hard way on that one).
Black pepper eo also blends well with bergamot (I'm from Italy so I'm a bit partial to it), not to mention the obvious spices - coriander, clove, juniper, etc. and even ylang ylang! It's wonderful in salves, for its antiseptic properties. I also love white pepper, it's a little softer, but can disappear in stronger eo notes.