I typically try to find a particular sound that catches my fancy...Jam with it on the keyboard to pick whatever key signature it plays best in...From there, I'll EQ and compress just that particular sound, as it typically is the focal point of my track anyway...I then create a few 8-16 bar loops of the idea and off I go...

From there I search for a drumkit that compliments the original sound, or a sound that compliments an initial drumkit.(If i started with a drumkit say...)

I then try to gather enough elements for a basic mix and work the track up until the first breakdown...(Drums/arps/pads/lead/bass/FX)

After the first breakdown I'll leave it alone for a week or so...

I like doing this because it clears the 'aural palette'...and there have been some occasions where I've come back to a track and thought "wtf was I smoking..." (The answer being weed most obviously ...)

The track layout that I seem to be favoring is : Intro =>Hook/Hookbuild (small build acting like a hook for the big one)=>Melody Segment=>Breakdown=>(introduce an instrument or two if progressive)=> Final big build => Melody + elaborations and modulations/Breakdown/End.

If it's a loop that I've generated myself, I typically try to elaborate on it a little bit rather than leave it loopy. Anything you put into an event is just a loop anyway, so I try not to dwell on it too much :P

Still though, I find elaboration to be the best method for me so far. "Oh, if it only had this sound on top of it...OH! If I tweak this filter now..." Songs typically produce themselves in this manner ^^.