Summarize:

Ingredients for candles may be purchased at arts and crafts store.  Quantities for each ingredient will vary, dependent on the size and amount of candles you plan to make. However, half a pound of wax equals to 10-12 small candles, and candles only require one wick each. You should check your mould tray for a point of reference if you're unsure about quantity.  Paraffin wax. Half a pound of wax should serve you well for a home set of candles. If you're feeling thrifty however, you can melt down old candles into fresh wax. Drops of essential oil. These are essential, and can be used if you want to give your candles a scent. Only a couple of drops per candle will be needed to get the scent. Baking tray mould. The size of your mould will determine how large the candles will be. Small muffin candles will burn for approximately one hour. Large muffin tray candles will go on for about three. Tart moulds and cookie cutters can be used as well for this, so long as there's a moulded slot for a candle to settle in. Pretabbed candle wicks. Making sure to get pretabbed wicks can take some of the hassle out of adding them into the wax. Dye chips. Dye chips are specifically made for use in homemade candles. They're small, but effective, so you'll probably only need around one per candle. You can eyeball the effects of the dye chips as you add them. Dye chips will give your candles a pleasant colour. One dye chip per pound of wax should be enough to ensure a bold colour. It's important to add your dye while the candles are heated. That way, they'll be able to disperse throughout the wax with stirring. Dye chips are designed specifically for use in DIY candle-making, so they tend to mix with wax very well.  Mix it in with a wooden spoon to ensure the dye is consistent in the candles. Essential oils are added for the sake of scent, and should be added to the pot as soon as you've turned off the heat. Paraffin wax needs to be 150 degrees Fahrenheit in order to be ready for pouring. If you have a thermometer at hand, place it in the wax and gauge the temperature. Check the consistency periodically. You can do this by placing a wooden spoon in the boiler pitcher and gently stirring the wax around. If you don't have a thermometer, wait until a thin film forms around the edges of your pitcher. If you don't coat your mould with cooking spray or petroleum jelly before hand, your candles will put up a hassle when you try to take them out. Because you'll ultimately be taking them up held by their fragile wick, you'll want to minimize that resistance early on. Excessive spray isn't necessary. Just make sure the bottom of each mould slot is evenly sprayed. Being thorough at this stage prevents hassle later down the road. Once the wicks have set, candles take up to two hours to harden completely. Set them aside, and occupy your time with something else while they settle.
Gather your ingredients. Introduce dye chips while heating. Heat the wax. Coat your tray with cooking spray. Allow the candles time to harden.