Fur jackets can either be fabulous, or terrible.
Long sweater are great for keeping you warm. Make sure they aren't too long or that they have way too much material, then it just looks funny.
Leather pants, leather leggings or just shinny pants can either look bold or make you look ridiculous. I think when you wear those kind of pants, you have to keep it pretty simple on the top, so that it doesn't look busy and overdone. (all these pictures are taken from the internet)