They're okay.
I recommend you to stick with no text, you can't seem to execute it well.
To improve on it, try a text which matches the theme and then use the image as a clipping mask.
They all lack depth except the first one, so you should try burn and sponge some spaces to to give it a deeper look.
The second one has too much negative space, which makes the sig look unfinished.
The third one I like the most, nice flow, effects but again a bit of negative space.
The main points you need to work on are Flow, Depth, using as much as you can of the space in the sig and your text.
You're doing well and improving.