I've had that plain oversized navy blue t-shirt for awhile. I have to tell you i'm a big fan of an oversized everything. It is so easy to dress it up or down by adding accessories or mix them with whatever style you want. Anyways, i has that shirt and a sequin ribbon that i cut off of my "too long" Ann Taylor skirt.
What i wanted to have is the same oversized navy blue tee with a little twist. I just sew the sequin part to the bottom of my shirt and it came out pretty fun and festive. I obviously worn that to work the next day. To make it more casual i added some black tights, jean shorts, and a plaid shirt.