Hi James,
Ok Lets see if this works
It should hopefully demonstrate the ability to lift a shot slightly when using a single light source. Personally I would never shoot anything without a reflector on the oppsite side. (Unless I was after really dramatic light/dark). It should hopefully be self explanatory but fire away with questions if anyone has any.
For the record I always work on my own and am used to holding reflectors up with another light stand or a chair or sticky tape - generally whatever is around. The fhird shot has got so much light on it from the gold reflector I would start to alter my exposure a little but these have been deliberatly taken at the same exposure.