I wasted a lot of time, learned a lot of information I wished I'd known in advance, and made a few mistakes throughout the process of cutting my wine bottles. I really appreciated Miss D'Orsay's post, but figured I'd fill in some more information that I've gathered.
First off, I ended up purchasing the Ephrem's Bottle Cutter from Delphi like Mrs. D'Orsay did. I remembered reading this post from Mrs. Crab Cake a while back and thought that a Diamond blade was my best bet, so I wandered into Home Depot with no clue what I was doing and basically duplicated Crab Cake's experience - except I don't know someone with the right (expensive) tool, and I did not walk out with what I needed. So know this, unless you have a Dremel tool, the Ephrem's Bottle Cutter is the way to go. The only downside is that it's a time-consuming project and I now get a LOT of junk mail (e-mail and snail mail) from Delphi.
So, here's my step-by-step guide from beginning to end to turning regular ole' wine bottles into awesome votives and vases.
I lived with four other girls last year who helped me drink wine, make sangria, and collect bottles from friends a neighbors. If you don't have these kind of connections or just don't want to drink that much wine, you can contact a recycling facility or even a wine bar and see if they'll donate their used bottles. In fact, we've run out of some of the colors I like, so we're thinking about going this route for some more. I'll let you know how it turns out.
After and while I was collecting bottles, they sat piled everywhere - in crates in the garage, under my parents' bed, along my walls.
personal photo. sorry, you've seen this photo three times now.
I left the bottles soaking in my parents' bath tub for about a week. I intended to leave them overnight, but I got busy. Even after all that soaking, it took a lot of fingernail scraping to get all the sticker stuff off. I suppose washing them with soap and hot water would do the task just as well in a shorter period of time. If you are going the soaking route, though, fill the bottles with water while filling the tub so they will sink and the labels will be completely submerged.
Step Three: Gather Your Supplies and Troops.
Other than the items that come inside the bottle cutting kit, you will need  plenty of matches,  ice cubes,  a plate of glass to sand the bottles on,  a candle stick holder or something to keep the candle upright and secure, and  some smiling volunteers. The actual cutting of the bottles has multiple steps, so it is easiest to have an assembly line going. Trust me, I tried some bottles on my own and some with a group - the group bottles went MUCH faster and look MUCH better.
The cutting device has a moveable center/back piece so you can cut different bottle heights. Keep in mind that you can flip the bottle so that the bottom part faces inwards for longer bottles and outwards for shorter ones.
The photo above shows the device turned in for the longest possible length, and below it's facing out for a much shorter cut.
Step Five: Etch the Bottle.
personal photo. David was a very concentrated and professional etcher.
This part is very important and really kinda tricky. The instructions say that you only need to put a "slight" amount of pressure on the bottle as you're turning it on the blade, but this is not true. I thought this meant that I should etch very lightly which caused my pressure to be very uneven which led to cracked and jagged bottles - no bueno. David, on the other hand, put a lot more pressure, caused an unpleasant grinding noise, and created bottles that broke perfectly evenly. (you can see the difference between our etching above - the clear bottle is mine) So, when etching, put enough pressure to hear the nails-on-a-chalkboard type noise, and make sure it's consistent pressure the whole way around.
personal photo by David.
This step requires patience and slow, steady rotations. Like the etching, the goal here is to get everything even - to evenly heat the bottle, you need to hold it above the flame and rotate - slowly - all the way around a few times and then a few quick turns for good measure. You need to be sure to hold it one eighth inch above the flame, or else your bottle (not to mention you hands, clothes, and just about everything else) will get all black and sooty like this:
Okay, I should have been fired (ha ha) from the flame job - eww and look how uneven the cut came out when I tried to do everything on my own.
This job is easiest done by the same person who does the flame part because it has to be done pretty much instantly afterwards. This is the easiest job - just rub a piece of ice around the hot etched line. You'll hear some cracking noises and voila! - the top should pull right off.
personal photo. David took over my job on some of the more stubborn bottles.
Step Seven and a Half: Repeat Step Six.
If the bottle doesn't break easily, you need to add more heat. This is the trickiest part. The directions say to rotate it over the flame again and it should come apart. What they don't say is that it may come apart quickly - while you're holding it over the fire. Make sure to hold on to both ends securely if you need to hold it over the fire for a second (or third or fourth) time. We found that the bottles we cut shorter were much more difficult to cut - we had to switch between the fire and ice multiple times. We figured that the bottles must get thicker at the bottom - so, the shorter the cut, the harder the break.
The kit comes with a strip of sand paper and a vial of sand to pour onto a glass surface (that you're not afraid to scratch up). The sandpaper is for the beginning and end touches, and for the rest, you dip the cut bottle end into water and rub it in circles in the sand. It dulls the cut end so it becomes smooth and grey.
personal photo. Momma spent a lot of time sanding these babies down.
The sanding takes a lot longer than you might think to actually get the final grey look that the instructions ask for. We really just sanded until we could rub our fingers on the edge without any worry of getting cut.
TA DAAA! Now you have beautiful, re-purposed, eco-friendly, creative, and cheap vases and/or votives.