First off, it's really nice to hear some fingerpicking here on Newgrounds, not many people posting that sort of thing;)
Really like the chord progressions and melody/riffs, and the transition from the slow to fast fingerpicking. It's hard for me to give you any 'tips' on where to take the track. I think, when you already have the 'bones' of a piece, then the best thing you can do is just keep playing it. Often it will develop naturally on its own through repetition, just follow where it leads, but try not to over-complicate things; in my opinion, it's often harder to write a 'simple' song, but they can certainly be the most effective/effecting.
Perhaps, when you're playing the song through, try to think of a lead vocal line/melody. This might help you develop the piece.
All the best