Thanks for asking the question stevelaba! Looking over Christopher's response is helping me too.

Here's a thought on working with a scale - how about taking a lead section from songs you like and identifying the scale/intervals used in the lead? I mean really transcribe, break it into sections and see how the notes fit into the scale/key. Are they bending/sliding into the chord tones? Does it go totally chromatic/atonal on you? Why do you like it?

Kind of an academic "geeky" thing but it'll give you an insight into some of your favorite playing and may reveal some tasty riffs for your own jamming.