I think going back to theory is the best way to go about this. Knowing the schematics and knowing where the notes are on the fingerboard. At the moment i'm learning the pentatonic scales. I was so happy when someone was strumming c chord progressions and I was able to do a pentatonic C scale with them...It sounded really cool even though it wasn't "lead uke" per se! it still made me look more of a "advanced" beginner hahha!!
those threads that kanaka put are pretty good resources. I'm such a noob to theory that some of what people are posting seems like rocket science!!!
but anyways PRACTICE PRACTICE and MORE PRACTICE and a little patience when reading the theory stuff!!