How to get candle wax out of a glass candle holder

So, I was burning a candle from my wedding (we used scented candles as wedding favors) and I wanted to get the remaining candle wax out of the glass holder. I tried tapping it out gently, but no luck (sometimes that has been enough to get the remaining candle residue out), so I had to take things a step further. 

I simply popped the candle holder into the freezer for a few hours, took it out, gently tapped it on the bottom, and the remaining candle wax came out! There was still a tiny circle of wax remaining in the bottom of the candle holder:

I took a butter knife and scraped it out in seconds:

Now all that's left to do is wash it out in some hot soapy water, and it should look like new (hopefully)!!!:-)...