I bought a huge Tee at a dollar store planning to cut off the bottom half for an easy summer skirt. There are several howtos on this site (e.g. http://www.cutoutandkeep.net/projects/wicked_easy_mini).
And then I got frugal :) and used the upper half to make a shrug to match. It is important to cut properly so that the skirt is not too short, nor the shrug too small. Both the skirt and the shrug have drawstrings to adjust the size.
My Tshirt had long sleeves, so I cut them off and used the cuffs to create the wrist thingies (armwarmers?). And I sewed on some novelty yarn as a decoration. One can use lace, ribbon, etc. instead.
This was my first sewing experiment ever (4 hours for just 10 stitches heehee), so it was nice to have a ready Tshirt to start with, rather than fabric and patterns.