Looks Like A Boxey Minivan How Do I Pick A Professional Business Outfit?

How do i pick a professional business outfit? - looks like a boxey minivan

I'm a big girl, but I'm also a little on the high side. I try to find you a chance business suit, but I do not get professional. I try everything that is good height makes me look taller and more Boxey. I also have no sense of fashion and a very low budget. Does anyone have any suggestions?