To draw the eye away from the midsection and towards the bust and shoulders, shirts should highlight the latter area whilst nicely skimming over the tummy. Keep detail in top and lower third of your body
Details on the hemline bring attention to the legs.Keep details above the bustline and below the hipline - for everything in between keep it plain and simple.
Highlight your best parts - usually the bust and/or legs - to help take attention away from the midsection.