Here is a siggy i made recently and yes my name on some other sites is smexxi. It prob. isnt that good though :\
hmm indeed it is crap. looks like you took a screenshot of a beziers screen saver and smacked a render on it and added text on paint lol. You should try looking into actual image editting software. GIMP is a good free one... Photoshop is the most preferred but is rather expensive. Then look up tutorials and you should be forging better sigs in no time.
The background is not matching the foreground. What I mean, the background is somewhat disturbed and not accentuating the foreground.
it needs a lot of work. Don't be discouraged. Just work harder on making it. Look at some tutorials online, they helped me learn the software and improve my skills.