Professional Perfumery Methods
The professional perfumery methods are a lot like the amateur ones, just a little different. The basic process of making perfume is the same, but the materials are not.
Pure ethanol instead of vodka. Pure ethanol makes a great solvent for even the most resinous oils. It is what all commercial perfumes are made with, except some boutique brands that make roll-on oil or solid perfume. If you live in a state where you can get 180-proof Everclear, then you can experiment with it and see how much better it works than vodka.
The only problem with Everclear is that you can't sell perfumes made with it. You also cannot get it in half the US states. If you want to sell your perfume, you must get perfumer's alcohol, which is alcohol made undrinkable with additives such as Bitrex (extremely bitter but no odor) or methanol.
You can get perfumer's alcohol from Snowdrift Farm, a supplier for the bath and body and perfume industry. There aren't many places that sell perfumer's alcohol due to special licensing requirements, but that is one of them.

This vial of rose makes 1/3 oz of perfume.
Different fragrance materials, not just essential oils. There are many more fragrance materials available, not just essential oils. If you only use essential oils, you limit your perfume blending possibilities. It's like wanting to paint a mural, but only having red and yellow paint!
There are also absolutes, fragrance oils, and isolated aromachemicals, all supplying scents that can't be produced with essential oils. Some plants are too delicate to be pressed or distilled; making an essential oil out of them is impossible. Jasmine is one of these plants. Absolutes are stronger and smell truer to the plant than essential oils, and are used extensively in perfumery.
Fragrance oils, despite what you may have heard, aren't cheap substitutes for essential oils. They are a completely different spectrum of scent, containing both essential oils and synthetic aromachemicals. Fragrance oils give you access to scents that you can't get naturally, such as strawberry, peach, and watermelon.

These scents are always synthetic!
Aromachemicals are isolated scent molecules that are either synthetically produced or refined from plant sources. For example, the compound vanillin is what gives vanilla its characteristic odor and flavor. Artificial vanilla flavor is usually pure synthetic vanillin. Natural vanilla has many more compounds than just vanillin, which is why it tastes better!
Strawberry fragrance oil, one of the most sought-after scents in the cosmetic and fragrance industry, is a combination of strawberry aldehyde (Ethyl methylphenylglycidate) and other compounds to round out the scent. Strawberry Kisses (and also Pear Glace) from Victoria's Secret? Chemical.
The use of fixatives. Remember when I described the problem of extracts vanishing too fast? Fixatives are a way to help make fragrances last longer. They are natural or synthetic substances that enhance scent and slow down the evaporation of scents that tend to disappear.
Why do fixatives work? They are very high in scent molecule count, often with no distinct odor of their own. For example, musk can enhance the scent and make its perceived strength stronger. It only takes a small amount for a big effect - with effective use of musk, you won't smell it, but the entire perfume will last longer and smell stronger. (Musks have been synthetic since the 1970s due to cruelty and endangerment laws.) Plant fixatives include many resinous, sticky oils and absolutes like benzoin and orris. They have an earthy scent that "deepens" a blend.
As you can probably tell, using the professional methods are not much more difficult than what you've tried already. A little change of materials, and you will get a better end result. However, I must say that the techniques given here are more expensive than the home-brewed. They require the use of specialized, more costly materials.
Using perfumer's alcohol and absolutes are only for people who are somewhat serious about perfume, but it is a fun, fascinating activity. It is definitely possible to get started cost-effectively; you don't need to shell out hundreds of dollars worth of absolutes!
The sample vial of rose absolute only cost $2 and made a strong 1/3 ounce of toilette spray. You can certainly experiment with samples of many precious botanicals for $2 - $4 each (unless they're really rare) and about $12 worth of perfumer's alcohol. If you are truly interested, my perfume ebook takes you through the process with step-by-step photos.

