Welcome to Basenotes. I don't have any experience with Jess, but will throw out some general guidelines based on things I've learned as a new person exploring fragrances:
1. You are right on target with samples. Sampling something on your skin, at your own leisure is the way to go. Smelling something on a paper strip won't tell you how it will play out with your body chemistry. And having the time to see how the fragrance develops/changes throughout the day (instead of just sniffing your wrist at a fragrance counter) will tell you a lot too.
2. There is no information on Jess in Basenotes' directory. If you could tell us what the scent is like (for example: starts out as gardenia then smells like a clean rose for a few hours), you should get some good recommendations.
3. Often you can get samples to take home (for free) from department stores. Sometimes, they can be stingy with them, though.
4. Getting samples or small decants on line has become more difficult, but there are reputable places that can provide that service. There's a nice list of online stores as well as brick-and-mortar stores here: http://community.basenotes.net/forumdisplay.php?f=19. You should also check to see if your city is listed. The online stores are in a topic after the country/city groups.
5. You can search the Basenotes directors for similar scents. Just enter the info in the "fragrance notes" box separate by commas (for example: gardenia, cardamom, cedar) and click search. It will give you a list of fragrances that contains those notes.
Hope that's helpful.