Issue with drawing in between hips and body

Every time I do a figure drawing or a drawing from any angle, connecting the white space between the ribs to the hips always looks stale, bland, and flat. Any advice or tutorials on how to draw that white space?

Depending on the pose:
If you are looking at it from a side view connect the bottom of the ribcage to the crotch with a curve line showing a little fat, then add some anatomical details like latissimus dorsi and show the iliac crest.
If you are looking at it from the front you can instead fill the empty space with the abs and a little fat for the pube.
It's hard to explaing through pure text

I find this also interesting as I experience similar problems with drawing the abdomen. Is it possible for you to post some pics of the process youve described please?
Ive read of similar drawing strategies but they begin from hips or down from shoulders.
Also im sadly ignorant of the names of individual/ particular muscles or parts of bones( apart from major groups/bones) & do not quite follow your design. With thanks🙏🙏🙏

**If not sketches then maybe link to them. But not being particularly interested in online techi things, im not sure if this is possible? **