your sigs are too big
in all sigs the render needs different placement and different size (except the 2nd one with the phoenix)
3rd sig needs more effects.
Overall they look okay, though they're really simple (just brushes, i have this set too
)
First one needs a different font.
The last one has a pretty nasty cut off at the right side of the render, could've at least taken a soft eraser and erased the straight line to make it softer =x
Keep making sigs and you'll improve
[What i said isn't meant to be taken offensively, it's just criticism, it's what helps you improve, and that's what you should want in your comments instead of "i love them!" since that's what you can say yourself, if you decided to post them up]
every sig needs
*Flow
*Depth (vector sigs need a diff kind of depth)
*A focal point (Something that draws attention, Mostly it's the render, sometimes it's the lighting, etc.)
*A background that fits the render
*A border. at least a 1px black one.
*some other things i forgot now, if i remember i'll post them up
And try to use more natural colors. Also try out the adjustment layers (Gradient maps, photofilters, Levels, Curves, etc.) Just experiment with them until you get the hang of it.
Hope i helped