Wax
To prolong its durability, you must light your candle for a maximum of 2 hours. You can leave it on for up to 4 a.m., but it will burn out faster. Before extinguishing it, make sure that the entire surface of your candle is melted. You will then avoid making the surface uneven and a tunnel forming around the wick, thus wasting the wax.
Do not remove the wax yourself around a so-called channel formed (if this is the case) around the wick in order to correct it. If you burn your candle long enough, the wax will melt evenly. Also, make sure to always cut off the black part that was burned off beforehand. So you won't have any smoke and the flame will be at a safe height.
Finally, if you have wax left at the bottom of your pot, a very pleasant alternative is to recover it for your diffuser if you have no more wax cubes.
How to avoid tunnels
Tunnel
When you extinguish your candle before it is completely melted, a tunnel will form.
Step 1
𝗩𝗼𝗶𝗰𝗶 𝗹𝗮 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻!! Simply wrap the top half of the candle with foil and make sure this wrap lightly covers the top (you still need to leave enough room for you to see the flame when looking from above).
2nd step
Let the candle burn until the top is completely liquefied. Remove the foil before extinguishing the candle using a glass or a candle snuffer. Once the candle has cooled, you will find that the tunnel is no longer present!!