Those look great. I did a couple dozen this weekend as well and noticed that the white spray paint at the end was an excellent finishing touch which really made my clear colored hot glue drips stand out. I'm told you can also find opaque white glue sticks which work well. Well done.
Simply they are ones I found at Joanne's . I cut the cord near the dial switch in the middle, took off the cheapie bulbs, unscrewed off the base. I traced and cut tow donut-like pieces of blue foam board that would fit with the PCV and hold the white center piece of each candle. I fitted them snugly around the candle, and screwed the base back on and replaced the bulb and slide it into the end of the PVC pipe. Then drilled a hole for the curt cord to stick out of. Th en I soldered a few lights together to a heavy-duty extension cork after I cut it's socket end off. Then just hot glue gunned the top donut piece to the top edge pipe.