1. Did you resize your render? Looks like you made the sig big because you didn't resize your render.
2. It's wayyy too dark.
3. The background of the sig doesn't match with your render.
4. Text&Font. You should try using a different font. Texts should bring the whole sig together. It's as much a part of your sig as your render/background.
5. Try adding a border. ^^
6. Place your text in a place that's more visible and a place where people look at more.
It's not a bad signature, really. It's quite good as your first signature, because you managed to put a nice looking background. ^^
However, the color is indeed too dark. It would be nice to see that the girl, since she's the primary attention of this signature, will be brighter than the background itself. Or you can play with Clair-obscure(sp?) with one line which you can focus in the middle and then the signature might fit more. :3
To make a border, it's easy. It depends on what kind of border you prefer though. Some like rounded borders, some like the famous 1px border and etc. It's all a natural preference.
I'll PM you with some details of how I make borders and such to not go off-topic here. x___x;
And the newest signature is nice, because the pink stands out. Plus, smaller signatures are always a plus. :]
But one thing that you need to keep in mind are the colors. Pink + gray does not fit well. Pink + blue / purple however will do miracles.
I have to admit that I'm sucky when it comes to colors too. But in this past few months, I learned a lot from my Art teacher. She thought me a lot of the primary, secondary and the tertiary colors and other fascinating things about colors and how to mix them or to make them stand out.
But the basic right now is to learn and experiment with the primary + secondary colors. Tertiary will come later, there's no rush when it comes to art.
Erm, I'll stop rambling nonsense and good luck with your signatures! ^^ (I sort of find the things what I said nonsense + off topic. D:..)