Can a skirt be altered?
Even shirts you are already wearing can be easily tweaked for a more professional fit. The sleeves of a dress shirt can be shortened an inch or two by an experienced tailor. The collar of your shirt can be easily replaced, although you may need to accept a white collar for contrast.
Why does my skirt stick out at the back?
Why does my pencil skirt stick out in the back? This happens when the waist is much smaller than the hips. You will need to add darts to the back to accommodate this and then your zipper should lie flatter. The other thing that might be happening is that your back and zipper overall are too long.