Curved and fitted cuts are yours! Your morphology is ideal for highlighting your femininity, so don't deprive yourself of it. Your upper body is the part to value. Feel free to wear low-cut tops, V-necks, bare your shoulders with sleeveless tops and fancy blouses. The wrap-over top is also one of your allies, as is the waist belt, perfect for emphasizing your slim waist around a soft t-shirt, dress or playsuit. If you have curves or if you are a little heavy, avoid adding volume with frills or with a straight cut coat and opt for fitted tops that are not tight, and fitted jackets and coats that go down on the hips or mid-thigh.
As long as you respect the balance and top/bottom harmony of your outfit, you can afford to wear just about any bottom. Jeans or straight pants, slim or bootcut (small preference for the bootcut which balances the silhouette), trapeze skirts, pencil, straight, shorts, it's free time! With a preference for the high waist that emphasizes the waist, but watch out for the side pockets if you opt for the low waist.
Avoid straight jackets worn closed, all loose and shapeless clothes that would hide your feminine curves. Forget dresses and coats that are too straight, square necklines, puffy tunics. We also forget the empire waists, even if it is very pretty and romantic, because they completely veil the waist and the hips. We also avoid very shouldered jackets which unbalance the silhouette. In short, no need to overdo it (patterns, volumes, fabrics…) with an X morphology.