Here is a simple way to completely reinvent an old jacket, by wearing it upside down creates a fantastic collar, and a wonderful fitted waist. Make sure it has a nice lining, and you're ready to go.
Then you may need to stitch in some darts around the arm holes, as you will see that when you put the jacket on upside down there are little bits that bag out, so you just need to stitch these up to create a flatter finish on the back. The best place to stitch these darts is on the already existing shoulder seam, do it so that you stitch on the inside, so that when you turn it the right way out you can't notice it. Its always best to keep pinning it and trying it on before you finally stitch it.
Once you have stitched in the darts, you need to cut the sleeves to fit the arm holes because you have made them slightly smaller by sewing the darts. Then pin them in place and keep trying on the jacket to make sure the sleeves fit right, once you are happy stitch them on, making sure the rough edges are on the inside of the jacket.
And then you're done!