Well, believe it or not, I'm on the deepest blackout song writing-wise of the last 6 months. It's always different for each song, but for this one I just picked my guitar, tuned it to Drop A, and started riffing on the 5 highest strings as if it was a E tuned regular guitar. I suddenly came up with the first riff (a lot of Mors Principium Est influence there, but brought down to my playing level) and I liked it, it sounded clear and punchy. Then the second riff was obvious and easy to achieve as it's the same thing played in the low strings. The third riff was pure Sybreed influence, and the latest one was a bit Scar Symmetry-esque, as I'm planning to go epic with vocals there, so I had to leave some room for them.
Cheers!