The perfume smell / taste is often caused by alcohol in the flavorings used. You can help reduce this by leaving the tops off your bottles for a few days. Some vendors use flavorings that have a soapiness to them too, and in a similar way, this can be reduce by a cap-off steep or aging.
As for how it's made, it's quite simple really. Nicotine is mixed into a base strength by combining it with either PG or VG or a combination - depending on the vendor and what the final desired ratio's of the finished
e-liquid.
Then flavorings are added (and additional PG or VG as necessary to get to the desired ratio).
Some vendors will also add other liquids like lemon juice, saline, vinegar, sweeteners, smoothers, colorants, distilled water etc.