I have two tips for you:
First tip:
Just go nuts!
Just fuckin' tear that fretboard appart, tremolopick, slap and tap as fast as you can, dont care about what it sounds like! JUST DO IT!
Then you try to play the same thing again, and again, and again, untill it molds into some kickass solo.
My second tip is to play after a mixture of scales.
I like to mix Aeolic, Blues, Diminished and Harmonic scales in to ONE scale.
Another tip to make an old scale interesting is to start playing your licks backwards!
Ive created awesome licks that way.
Check out my 2nd solo in our song:
http://www.myspace.com/lastshoutofficial
The first and last part is just going through the scales and ending with bend + pulloff, the parts in between where just something random.
Edit:
What the hell, il tab out the tapping part of my solo!
E|19-15-12-19-15-12-
And then I just play the same thing on the other strings.
This is a thing Lynch, Reb Beach and Dimebag used alot: Making a onestring lick, and then you play it on different strings, and maybe move it around the fretboard as well.