Yes, well, but, look at your eeveelover banner with Kindra and other Pokemon. I cannot do that kind of background as of yet. All I know is the Render->cloud effect. So, that is what I use for all my banners. :|
And, while your banners did look basic, you still had a fantastic command over the brush. I cannot design properly with brushes, my hands do not move in a certain way, like how an artists hand move. My overall drawing is horrible.
So, I will consider your offer and join your shop, but, not already. Maybe after a few weeks. I'm still not confident enough.