It really depends to be honest. First it depends on the girl, if she's hot or not, if a girl is sexy, she can pull just about anything off, but if not then some things will make her look even worse. Also it depends on the jeans and the t-shirt. Tight = yes, baggy = not so much, but again those tie in to how hot she is without clothes. Hoodies can also be hot, but it depends on the person and how baggy they are. Long story short, hot girls can pull it off no prob, and less hot girls it just looks "neutral" on them, and tight is good, not necessarily chocking you, but form fitting clothes is a definite plus.