Hi,
Use the flux cored, leaded solder - it flows much better than the lead-free type and doesn't need such a high temperature, and for our "small" jobs its not going to affect the environment. I normally run my temperature controlled iron at 280degC for leaded solder.
I use the Veroboard with gold plated strips, but also clean it with meths (denatured spirit) to remove greasy finger prints. I've never bothered to clean freshly stripped insulated wire, nor small components.
When I'm using the "Verowire" hookup wire the iron is set to 350degC to melt the special insulation, which becomes a flux for soldering.
Most bad joints come from trying to solder at too lower temperature. Have a hot iron (50W temperature controlled) with a good thermal mass, heat up the joint quickly and dab it with solder.
Some larger components with shiny tags, that have mechanically assembled rather than soldered in manufacture, sometimes need scraping clean, since they seem to a very thin layer of possibly lacquer on them.
If you are using wire wrapping, make sure the first couple of turns have the insulation on them, since this removes the mechanical stress on the bare wire.
Ian