This $4.00 LED light is what I use when I really need to illuminate my Kobo Mini screen.
http://www.rayovac.com/Lights/Genera...-Keychain.aspx
I hold Kobo Mini with 3 fingers in relaxed curl under the reader and 1 finger on top of screen bezel at top corner. Bottom corner of reader is under side of my cupped hand. Flash light is held below thumb knuckle between thumb and palm close to flashlight lens with light shining on cupped palm of hand so it reflects even light onto screen. I can tap screen with thumb of hand holding reader to turn page or with other other hand.. This flashlight is something I always carry anyway. The special reader lights I have are too cumbersome to carry in my packet with my handy 5 inch reader. I often use this at theater waiting to watch a movie. At home might use a small desk light or the flashlight.