The efficiency comes from testing in parallel rather than in series, which is the thing nobody tells beginners.
Do not pour one candle, test it, adjust, pour another. Pour three or four jars in the same batch with different wick sizes: same wax, same fragrance, same pour temperature, same day. Cure them together, burn them side by side.
One week and one afternoon, and you get a comparison rather than a data point. That is the difference between months and a fortnight.
How to run the burn:
Burn for four hours, which is what a customer does, not one hour.
Look at the melt pool at the two hour mark and at four. You want it reaching the glass by about two hours in an 8oz jar and staying a sensible depth.
Note the flame height and whether it flickers or mushrooms.
Weigh the jar before and after if you want a real number, consumption per hour is the most objective measure you can take and it separates two wicks that look similar.
Then burn again the next day, because a lot of problems only appear on the second and third burn as the pool deepens.
One more thing that saves a season: change one variable at a time. People test a new wick and a new fragrance together and learn nothing.