I did this a few years back and threw in a Madame Leota effect, and it turned out pretty well!
What you need to do is either cruise through your local second-hand store or just save bottles and jars of different shapes and sizes that you were going to throw out, anyway. Fill up your sink or a bucket and put your bottles and jars in there to soak the labels off completely. After a few hours, most of them will just separate easily from the glass.
If you're handy with Photoshop, you can create your own labels. But if you're like me, the person who keeps saying you're going to learn Photoshop, but somehow never gets around to it, you can search around for cool labels to download. There are plenty of creepy labels available on Etsy, but you can also find free downloads, like this one, from Catch My Party.
At this point, all you really need is a pair of scissors and a glue stick, and you're in business! Fill up the bottles with tonic water and position a black light where it can't be seen, but it will shine down on the bottles, and you've got spooky, glowing bottles! (Tonic water is black light reactive.)
If you're really ambitious, throw on a pair of disposable gloves and take apart some fresh highlighter pens of different colors. Take the ink cartridge and squeeze it into the tonic water for different colored "potions." Throw in some plastic eyeballs, spiders, or whatever you want, to give yourself some variation in your contents. You can even drip some wax on the lids, or use a glue gun to glue down some sisal twine and then drip wax on it for a real, homemade look.
Most of all, just have fun with it, and let your imagination roam!