Another user of Fluro's here. Good for general lighting, but I strongly agree with stuckinthemud's strong single light source for picking out blemishes, and also for plotting centrelines with the shadow of a string.
Daylight is great for picking out blemishes too.
Raising the grain with a wet cloth between grits of sandpaper goes along way, to help show up blemishes that you thought had been sanded out.