I've made a few along the way using various essential/fragrance oils. I tested one fragrance out in January and it's still going strong in April. I just made 50 for a Florist friend - bottled, labeled and blended. The thing is, it's very expensive to make when you are using good oils. However, I guess that's what separates good diffusers from bad. I've personally bought some that last for a week. This blended rose fragrance has been great and people really like it.
I can't believe I labled and filled 50 - 9oz bottles without getting a drop of oil on the bottle or label! hehe. That's the beauty of funnels! hehehe!
What fragrances are you using? I've sorta been disappointed with the commercial blends I've tried. Of course it probably doesn't help that my favorite fragrances are herbal and citrus which tend to be lighter scents.
The citrus doesn't really hold dmac - However, I did make some with a citrus fragrance from Snowdrift farms called "Satsuma" that seems to work. I make a lot of rose as I found 2 great scent from Wholesale Supplies Plus that I mix together - English Tea rose and Fresh cut roses. It's not overpowering or sickening and lasts for months!