One very important tip to a new solderer. CLEAN! CLEAN! CLEAN!
In order to have a good joint, you must thoroughly clean both parts to be soldered first. It helps to sand the metal with a suitable sanding pad and then clean with alcohol. Do not touch with your hand, the oils in your skin will weaken the solder joint. On difficult to clean parts (like the inside of a ferrule) a good solder flux will greatly help.