A simple concept, and even at the level you are at I can give you a couple of pointers without having to teach you much
You appear to want to go for a dark and menacing theme. This leads itself to using dark colours for the most part. The largely white background belies the true intentions behind the piece, so you would want that to be a dark colour, maybe black, or something close to black. The text you could then have white or red, anything that has a menacing connotation and will stand out enough against the dark background. A different font will help to alter the mood of the piece too, I'd go for Argel font, Burton's Nightmare, Ghastly Panic, Northwood High, or Rothenburg Decorative, fonts that have a more gothic feel to them (think that most of those I listed are available as free downloads from dafont.com).
Slight details in the background can aid the piece, as they can help to break up the monotony of a single block colour. If you want more focal on the figure then you will want to bring them in towards the centre a bit more to around the third line, as that is where the viewers eye will naturally want to gravitate to.
For the most part I like to take the approach of less is more with darker signatures. I'm not overly keen on using much text in signatures anymore either, but that is just a personal preference that I have so that the viewer can focus on the image easier, and they can flow from one focal point to the next, and see the depth (if any).
Keep it up though, and hopefully within the next couple of weeks I can start recording my class videos for the gfx school