I use a small (one AA battery) LED flashlight, which lies on the platter pointing any direction I choose.
Costs virtually nothing, available virtually everywhere.
A headlamp wouldn't work for me, since I often want the light shining through the stylus toward me. My Magic Eraser wedge makes a handy light diffuser to avoid being blinded by the LEDs.
Simple, cheap, flexible. I can put $50 toward hiring some kid to wash some of these LPs! ;-)