Your sigs tend to be overcontrasted and rather messy looking tbh. Do you use GIMP? Your sigs also need a 1px black border and the text placement, fonts and colors can certainly be improved. Just keep trying. I was the same way.
Well, if you look at the last one, there are tons of splatters and other brushes everywhere along with C4Ds gone rampant. This goes to the point where i really cant tell what that render is. Just be more sparing with the junk you throw around the sig.
overcontrasting is the first thing i notice. they lack depth, and there are way too many effects that make things confusing. i do like the black/yellow though, but the text on that timeshift one is a little overdone as well. make it simple and blend in EDIT: i scrolled past the librarian text as well. for one, never use chiller except in rare cases, and also, it sticks out waaay too much
I first noticed, no depth, no flow, the brightness, the single colored background, cubism, and that's pretty much it. Put the cubism effect down. It's ruining the signatures, and breaking the flow. I know this might be hard taking this, but you need to experiment with your other effects available to you.
I wanted the text for that one to stick out a lot, because my nickname is The Librarian. But I'll see what I can do with a different text. and the last three ones have been finished for weeks, I just hadn't gotten around to posting them yet.