-- Fragrance oil (optional if you want your candles scented)
-- Scotch tape
You can find a lot of these items at a craft store or online.
Heat up the wax
Place the wax flakes in the glass bowl. Then, place the glass bowl in a pot of water. Boil the water and make sure that all the wax has melted. If you want, add some fragrance oil to make scented candles. Be careful when melting the wax!
Prepare the candle wicks
While the wax flakes are melting, prepare the candle wicks in your coffee mugs. Take the candle wicks and put one in between two chopsticks or pencils. Then, use the scotch tape to tape the pencils or chopsticks together so that the candle wick will stay upright, as shown in the picture above.
Pour the wax into the cups
Once the wax has completely melted, pour the wax into the coffee mugs. Make sure that the wicks stay upright. Let the wax dry completely. Then, cut the wicks so that there is only a small part sticking out of the candles for the flame.