Prepare the tallow for candle-making by heating it until melted on an indoor range or outdoor fire. The tallow need not boil; it simply must be liquified to a point where it is easy to work with.
Dip cotton candle wicks into melted tallow, allowing them to soak up as much tallow as possible. Then carefully draw wicks out of tallow and hang on frame or rack to cool.
Once that first layer of tallow on the wick is cool and solid, repeat the dipping/cooling process until candle reaches desired thickness.
Another way to make tallow candles involves the use of candle molds. This process is more challenging, as it is difficult to make candles of a consistent form, but it is quicker than the dipping process. Take the time to dip the wicks repeatedly if candles of a uniform nature are desired.
After dipping the cotton wicks in the tallow the first time and allowing the wicks to cool and stiffen, place them carefully into the center of the molds and pour necessary amount of melted tallow into the mold. Allow to cool.