I don't buy essential oils from MLMs because of the high markup (and sometimes business practices I don't want to support), but I do like essential oils.
I love getting them from Eden Botanicals because they also sell very tiny amounts of the really expensive oils... you can get 5 drops of rose otto for like... $3, I think. I know 5 drops doesn't sound like much, but if you're making perfume, it'll add quite a distinct rose fragrance to it.
Peppermint also repels mice, I've heard.
My best friend ordered me a piece of ambergris a few years ago (shipped from New Zealand - marked "amber" on the customs slip for reasons I'll not explain here), and I used it to make a tincture for some of the perfumes I've made. I can't stand the synthetic fragrances, and Florascent (which doesn't have synthetics) is kinda pricey. I used everclear instead of vodka. Vodka has a lot of water in it, which can make perfumes separate and have a cloudiness I don't like. I refuse to order "perfumer's alcohol" because I'm not selling my perfumes, and I don't like the idea of toxic compounds added to alcohol in my perfume just to make sure nobody drinks the stuff. Sometimes laws are ridiculous.
I also put some of the ambergris in jojoba oil so I could use it in solid perfumes, which seem to have a different scent profile than alcohol ones.
Have any of you tried agarwood? The smell is off putting at first, and you just want to use a tiny tiny tiny amount... but if you let the perfume age, the tiniest hint of agarwood is woody, exotic, and intoxicating - especially if mellowed by ambergris and some sweeter notes like neroli and jasmine.
Yuzu is the most amazing and effervescent citrus smell I've ever encountered.
Champaca is indescribably sensual, like the taste of the warm, clean skin of a lover after a shower together.
Good orris root (without a dusty smell) is beautiful while grounding, and helps round out and blend other flowery scents.
I prefer a touch of oakmoss over violet leaf for a green note in a scent.
Rose de mai is sweeter and fresher than Bulgarian red rose otto, but red rose otto is such a distinctive classic that I can't skip it when I order more samples for another batch of scents.
Carnation is much spicier than I'd imagined. Green and white cognac (made from wine precipitates) actually smell like wine in perfume.