As discussed in Inverted Triangular Body Shape, the aim it to highlight the lower body.
Few pointers to keep in mind while buying the Denim.
1. Since your lower body is narrower than your body, avoid the skinny fits. The skinny fits will highlight the narrowness of your lower body and in turn, will visually make it seems heavier upper body then it actually is.
2. Have design details highlighting your thighs and hips. Any design detail or the wash or cuts on thighs or hips will widen the lower body.
3. Make boot cut/bell bottom or slightly looser type of denim your best friend. Straight fit should be your second choice for denim. if you are medium to large then you can wear slightly narrow hem.
4. Low rise / Mid-rise / high rise all work well with this body type. As a style tip aways opt for mid-rise, it visually also elongates your body. If you have a midriff or D cup and above bust circumference, then avoid the high rise because that will emphasize on the heavy midriff.
5. Buy lighter colors like a grey or light blue, it will add an illusion of width to your body
6. Don’t buy styles or shapes that styles and shapes that will have have a slimming effect for your lower body.