The t-shirt, our most tried-and-true warm weather staple, will get an upgrade this spring. Look for the new and improved versions to feature unexpected flourishes, demure cut-outs, asymmetric and cropped silhouettes--and yet remain as versatile as ever. My favorites include this one-shouldered , this tie-trimmed , this cut-out , this knotted , this slit-sleeved , this scalloped , this pleated back , this frayed and this ruffle-accented .