If all else fails, go for 300W [just kidding],
tutorial:
http://www.aaroncake.net/electronics/solder.htm
One thing that shows your soldering iron tip is too hot .... many years ago I had a
cheapo Radio Shack soldering iron, non-temperature-controlled. After having the iron
turned on for a couple of hours, the tip was already starting to pit and deteriorate.
OTOH, I have been using a temperature-controlled iron for the past 7-8 years, and
the original tip still looks like new.