Millions of riffs, no songs...

Okay, so I have no problem writing guitar riffs. It's making full songs that seems to keep getting me. I'll make a main riff that I want the song focused around, but then it just goes blah after that. Here's an example of a basic riff I've written:

e|-----------------------------------
b|-----------------------------------
g|-----------------------------------
d|-----------7-7-----3-2---5--------
a|------0-3--5-5---------3-3--------
d|-0-3-------------------------------

and then there's a "build-up" version

e|--------------------------------------------------
b|--------------------------------------------------
g|--------------------------------------------------
d|------------7-7---3-2---5-3/7--------------------
a|------0-3---5-5-------3---------8-7---8-7---8-7--
d|-0-3--------------------------8-----7------8----9-

All I end up doing after playing these riffs is falling back into strumming some power chords... any help on building songs would be nice... like what could I do after this???

The method I like to use is variation. Just take away some of those power chords and sunstitute some new ones or change around the order you play them. This is more of a classic style. You could change the riff around.

Play the D5 power chord and then use the 0-3 hammerons as a little fill or something like that. Then go to the C5 power chord and use the 2-3-5-7 runs as a fill. That could be ok I guess if it works for what you are trying to do. Here's a tabbed version of what I'm saying.


----------------------------------------------
----------------------------------------------
----------------------------------------------
--7-7-7-7-----3p0--5-5-5-5-5/7--3p2p0---------
--5-5-5-5-0h3------3-3-3-3-------------0h3p0--
----------------------------------------------

Thanks... I'm going to put a version of this into work and see if I can't produce something worth recording... thanks for the help again...