If you have a lot of candles you probably had a time when you spilled some wax on glass. When you have was on something that is glass you can clean it rather easily with just a few simple tools. You do want to be careful not to use anything abrasive so you do not scratch the glass in the process.
Step 1 - Scrape Off Excess
You can remove a major portion of the wax from the glass with a plastic scraper. Run the scraper over the top portions of the wax without moving it back and forth like your digging it at. Keep the blade at a steep angle in order to scrape as much as you can.
Step 2 - Freeze Remaining Wax
Place an ice cube over the remaining wax remnant and let it sit for about 20 minutes. The wax should be frozen by then.
Step 3 - Scrape Again
Try to scrape the rest of the wax off after it has been frozen.
Step 4 - Warm with Dryer
If you still have some wax on the glass try to use the opposite of freezing the wax. Use a hair dryer and heat the was up until it is pliable and soft. Wipe it off the glass with a soft cloth. Clean the glass with some glass cleaner to remove any film or fingerprints.