Like most budding guitar virtuosos, you're probably sitting in your bedroom practicing scales that you learned about from one of many guitar websites. You've repeatedly played the blues scales, minor and major scales, and even ventured into modes until they've become second nature, however, none of the sites you've visited ever taught you what to do with the scales once you've memorized them.
Many of the guitar lessons online show players how to play solos and licks by famous guitarists, but the purpose of learning scales is so you can create your own solos and licks. Yes, you'll start out learning what other guitarists play, but what truly contributes to the development of your own style is how you blend what has been done by other players with what you have created.
The key to developing good solo ability with your own distinctive edge is to think in terms of variation. Ask yourself how much space you can put between notes, combined with consecutive notes of closer interval, when and what note should you bend, hammer-on, pull-off, slide into or away from to form a unique melodic idea.
Take the Em (natural) scale at the twelfth fret for example. Essentially in this position we have the Em scale in two octaves. The first octave starts on the sixth string, twelfth fret (E), and ends on the fourth string, fourteenth fret (E). The second octave picks up at the fourth string, fourteenth fret (E) and ends on the first string, twelfth fret (E). If your using scale boxes, add the second and third degree (F#, G) of the third octave on the fourteenth and fifteenth fret of the first string.
Typically It's best to begin a solo on the Keynote of the chord progression your soloing to. In the case of a progression in the key of Em, you'll start at either E of the sixth string, twelfth fret; fourth string, fourteenth fret; or first string twelfth fret (this does not mean you always have to start a solo on the note of the key signature, but it always works well; more on that in a later post). Decide whether you want to slide in from above or bend into to the E note you've chosen. From there think of ways you can make your solo sound interesting. From the E you may want to jump the seventh degree (D) and sounds wonderfully in contrast to the E. From the seventh degree you can walk back to the fifth degree (B), hitting a sharp fifth (C) on your way, then end on the fourth degree (A) and accent it with a little vibrato.
The above is just one simple example. The possibilities are limitless; you just have to search them out to find what works. Try making your own note sequences and visit my website to learn more about melodic variation and learn some variation exercises.