Hello, this seems to be your first post in this forum. :D
Getting involved in graphics is a bit of a commitment, but if it's a hobby, then I suppose it doesn't matter. Out of the three you posted, I have to say that the first is possibly the best.
Something that I would suggest to most graphic artists is not to experiment with text, since even the most advanced artists even have trouble with it. Text can easily make or a break a tag, and with such an influence, text is usually avoided in signatures. But if you acn make it good, the sig can look a lot better.
I'll be honest, I'm not a huge fan of the text in either of these sigs, but I will say this: the font color in the first tag is a nice attribute to the tag since it matches the color of the effects.
Speaking of which, color is also a major part of signatures. Your second signature has potential, since the background effects are neat and everything. The green and blue colors match nicely with the focal. But then you have red font, which sharply contrasts the green/blue effects.
And then you have the white background of the focal in the second signature (which is the robot), and also the focal in the third sig (Teddiursa). The images you used in these sigs are called "stocks" because they have a background. If you want a focal without the background, that's called a "render." You can find a variety of renders on
Planet Renders (note: you must make an account to download any renders).
Your placement of the focal is nice in the second one, although I can't exactly say that for the first or third sigs; you typically want to center the focal, but not completely center it. Yet you also don't want put the focal off to the side.
Just keep playing with signatures and effects. You will get better as time passes. Some people like to follow tutorials, and we have quite a few of those in
here, but you can find other tutorials on other sites like
Deviant Art. You can also google "GIMP sig tutorials" and you can find a variety of sites from there.
Avatar: In memory of ieatwyverns <3
Thank you, Vasco <3