Well, rosin core solder and 'tinning' are essential, as that 'thread' continually runs through this thread. For me, the endless annoyance is the large drops that will not become smaller and refuse to 'stick' to the object unless LARGE. I solder the tiny wires that come loose and once I soldered wires on the bottom of an OM-2 and it took about 60 minutes to get it right (and about 24 curse words). I use an old Radio Shack soldering iron that looks like a thick pen. NO adjustments. NO luxury.
Thank you for all the advice. This operation is harder than one would think but I will re-read your various bits of advice and see what gets repeated over and over again in order to prove the correct paths to follow. - David Lyga