Some more information on soldering, given the op wanted to work toward perfection:
Why Wet cloth and dry cloth?
The use of a dry cloth removes the excess flux 'before' you start soldering (most important tip)
The use of the wet cloth removes the flux residues after the joint has set, and you have finished soldering.
However, a note to those plumbers who insist on wiping around the joint after the solder has been applied, to make a neat looking 'wipe' mark.
This is a habit from the days of leaded solder when the plastic range of the solder made it such, that the solder was still mushy and could be worked for a few seconds after soldering - I too had this habit of wiping around the joint - but it is not needed.
Lead free solder has a different 'plastic range' and will set quickly. If you can wipe away lead free solder snots, then you have made the following actions that are just not required:
1. You have applied too much solder in the first instance risking waste of resources, time, money.
2. You have applied too much heat in order that lead free has plastic range which risks oxidising the joint.
3. You have risked 'cracking' the joint because you have touched it during its 'setting' stage.
If we wish to move our existing skills to those of mastery we sometimes need to recognise 'reasoned' scientific arguments. If people wipe around their joints and they have always done it, and had no problems, then they are masters of waste, and plug their ears when others advise - this is also an outcome of mastery, because we are capable of doing things the wrong way for years, but still achieve a desirable outcome - I am guilty of this too, but perhaps not for soldering!