Making Rock Riffs and Solos?

Im getting better at improvising rock n roll solos, but can anybody help me come up with some rock n roll riffs? what kind of feel do they have to em? chromatics? eighth notes?

Chromatic stuff is always cool, odd, easy to play fast but can be hard to find right time to throw them in. 16-notes are cool but can be hard if lots strings are involved. I like 3 note/per string stuff. Speedy, cool and easy to play. Strictly alternate picking. Triplet feel is usualy involved in sweeping pattern too. Playn´ lick in groups of 5 notes/beat are damn great too. Usualy when playn´ string skipping stuff, I play ´em in groups of 5.

PS. When it´s shredding, 8-notes aren´t welcomed.

Black1ce,
Did you check my lesson site ? Lots of ideas on there. I'm no shredder though...mostly pentatonic based rock and blues riffs. Give 'em a listen - good for new ideas anyway.
-Bob
http://guitar-wav.com