There are many ways to wear stripes. As you can see above, they can be dressy, like Solange's suit, or they can be a fun part of a more casual ensemble -- like actress Rosie Huntington-Whiteley's loose top.
Whether vertical or horizontal, they can create visual interest. That said, you've gotta be careful and make sure that the direction of the pattern flatters your shape, because stripes can accentuate problem areas.
Regardless, stripes are totally in.