Anyway, I also had this problem, as did ryoko (he hated me for saying his sigs looked samey lol) and most other gfx artists I know.
But you have to admit using the same bg in 7 sigs is way too much, every sig should be different, not very very similar, or what's the point in creating new ones? Just edit the old one
To get out of this, try the following:
1. work on a themed sig - possible peace, serenity or even christmas, summer, that kind of thing. Gives you a focus to work towards.
2. Take a break, and come back with new ideas (This one worked for me, I used to do what you did, making loads and loads of sigs that looked pretty similar)
3. Experiment (this one should be as standard, it's how the killer sigs are made
)
Anyway try a couple of those and see what happens. The results might surprise you
(Here's my comments for your sigs - yes I think they do look repetitive, as explained above. The sakura one is the best one by far, everything "fits" more than in the others)