Well what I generally do is make multiple varations to the same sound by either using seperate FX and also maybe changing the key or even the sequence, but all while still using the same sound. Hope that makes sense too..ha haYeah as I said it's pretty much done, and the fact the same pattern runs through the tune is the only bit I'm unhappy with but at themoment I just can't work out what to do.
Another thing I was just thinking about is maybe even add another synth noise after the break in addition to the other sound and pattern.
Maybe just something up in the high frequencies to give a differant perception to the sense....
I hope that is helpful amigo. Just stick with it and keep hainv fun making the tunes. As long as you enjoy doing it, things will come together. All of this just takes time. ;)