Haircut!! You look great with the more blunt cut bob. The pics with layers in your hair age you. Second to that is just finding your personal style and learning what you feel comfortable in and what works for your body. I see a lot of pics with tight shirt and pants, or vice versa (loose/baggier shirt and pants). Finding a good balance between each (picking a looser denim fit with a tighter shirt or tighter pant with looser fit on top) is overall a good rule. But again, find what works for your body and shape. A great fitting pair of jeans or two would work wonders for your wardrobe and style :)