POORLY PLACED BUTTONS
When fasteners on a shirt or sweater are too widely spaced above and below the breast area, it will gap unattractively.
EXCESS FABRIC
It kills the look and fit. In the industry it’s called a "grin" when excess fabric hits the crotch. It’s not a happy look.
Look for cheap fabric lining (like rayon). It can shrink once it’s dry cleaned and ruin the look of the garment. The wrong lining can make a garment look matronly.
Shopping Bargains
UNFLATTERING POCKETS
When pockets are too small, they can actually make your butt look bigger. When they’re stitched on too high, they flatten out your butt.