When I look at your banner I see Pink first, and "Blissful Boutique" second. The Eye is drawn to color, this is why white backgrounds work best for product photos, and that is why they can work better for banners and everything else we read. IF you are going for a more simple look I would suggests switching the font color & background color (and getting rid of the outline), but if you are going for a different style (Funky, Trendy, Girly, Vintage, etc.) you may want to do more: add photos/clip art, change the font style, add a paler background color, have both a non-white font color & a non -white background.
There is unfortunately no "secret to the art" It is mostly just playing around with colors/pictures/fonts/styles until you find a combination that you like & that accurately represents the over all style that you want your shop to be.
I would suggest looking at other shops similar in style to yours to get a little inspiration, & figure out what you do & don't like some what before you start.