Lavender is always a popular aromatherapy scent, mix it with vanilla or jasmine, and you won't be able to keep it on the shelves. Something citrusy, like bergamot with lemon and maybe a little sage or geranium to keep the citrus from being too strong is a great mix for an energizing scent. There's always the ubiquitous Eucalyptus Spearmint, everyone carries is, and it really is a great fragrance. I also love Chamomile alone, but it also blends well, and as with Lav, people are familiar with the name, so they are more prone to sniff it. I've noticed that a little exotic is cool, but people get weirded out when you use too many obscure oils. Then maybe a Cedarwood mix, to appeal to those who like the heavier, romantic scents. What I would do is go to BBW and see what combos they have, check out the selections of essential oil mixes from Sweetcakes, they have some amazing combos, and write down the ones that appeal to you, then start mixing and see what works!