Keep the wick trimmed, this will help avoid sooting, our candles have the maximum scent load in them and certain scents can soot a little.
Extinguish before replacing the metal lids.
The glass 0r tin will get very hot, place on a surface suitable and do not handle whilst lit.
All the reclaimed bottles will have some wax left in the bottom due to the 'punt' the large indent in the base of the bottle, we cannot do anything about this.
If you have a wax melter for 'melts' you can use the wax in the bottom of the bottle,
Warm some water in a pan, enough to reach a quarter of the way up the bottle, place the candle into the pan and re-melt the left over wax, DO NOT let the wax boil, pour into muffin case or any heat proof object, allow to reset, you can now use this in your melter.