Back to the costume. This is one of the outfits she is seen in casually. She also has a jumpsuit outfit that is cool, but I don't own a purple jumpsuit.
The outfit is easy, if you have the pieces, the only thing I spent time on was recreating her hair.
(I was trying to imitate a pose I saw her in, but it is hard to flex with a crescent wrench in your hand)
Step 1: Clothes
White Tank (I used a white beater with a white simple tank under)
Step 2: Hair
As you can see in the third and forth picture, there are four sections of hair for Winry. The pony tail, each of the sides that hangs down, and the bangs. (my bangs merged with one of the sides)
I used a straightener to get my hair to lie as flat as possible, as anime hair can do when it wants to. I also did it to help the pony tail kind of stick up a bit in the back and be a bit more prominent.
Divide it up and straighten it out. I straightened it before putting my hair back and after, in an attempt to tame it. Also, make sure the side sections stay in front of the ears, like Winry, try to just take hair that will more naturally fall there.