If they have heavy hips they shud stay away from short kameez and capri's as well.. they shud select a medium-length kameez. If they're top-heavy then it's best to avoid fancy embroidery around the neck..this draws attention to the problem area's.
If u have toned arms.. most sleeve lengths wud look nice.. but full sleeves have a slimming effect. Try and stick to single colors.. and small prints :)