There are many ways to make emergency candles. I could probably google how to make wax to make candles and find a ton of sources teaching how to use different methods. I want to give some basic ways to make candles from using old candles, Crisco (artificial lard, lard works well also), or olive oil.
First, most candles are made from paraffin wax, so you could go to many craft stores and get some to make candles a little easier, and with intent.
I will stick with candles in almost an emergency, or cost saving, situation.
If you have old candles, you should melt the wax, by placing the candle jar in a pot of hot water. Slowly bring the pot to a boil, or until wax is melting, whichever comes first, and just wait for the wax to melt completely. Then, you will do this with all of your other candles. Add all of the candles to the same jar and keep them melted. Add a cotton string that you can buy almost anywhere, tie it to a metal weight of some form and drop the weight to the bottom. Make a stand to hold the string up in the center and let the wax dry.
Jarred candles are typically much better, because it enlarges the flame, protects it from wind, brings more light out by refraction, makes them a little safer, and keeps the wax in the jar as it melts. My recommendation is to envelope the wick (cotton string) in the wax to get a bit in it before setting it up to dry.
You can use Crisco Shortening, or lard. You can use a whole can by using something such as a clothes hanger to push the wick to the bottom, or I prefer adding the Crisco to a jar if a jar (mason jar) is handy for the above reasons.
Olive oil typically is one of the better and healthier cooking methods, but it has a shelf life. Don’t dump olive oil out after use, or after expiration. Use it as a lamp. Make a stand for the wick out of wire or paperclip to be held up, just about a half inch above the oil surface. Make a small spring like shape at the top to wedge the wick into. Shape the bottom to hold the wick in the center of a mason jar.
You cannot use olive oil in kerosene lamps because it is thicker and heavier, so you must use it in a lamp designed with a short wick, so it can wick up the distance to the flame.
Hopefully, this helps you with your emergency/cheap lighting when needed. I may add a video showing the methods soon… we’ll see.