Shopping for school clothes with my teenage daughter - not fun! Neither of us have much patience with shopping. I haven't sewn for her for a long time, but after this shopping trip, I am ready to try again. (Sewing couldn't possibly be worse than shopping!)
Here is what I did.
1. Went to JoAnn's. Patterns were on sale for $1 each. Bought five patterns for what I thought were cute/stylish shirts. Figured that if she didn't like all of them, she would probably like some, and at $1/pattern I was willing to gamble.
2. Looked through my stash. Found a man's XXL t-shirt I bought at a yard sale for 25 cents, plus some white knit cloth I bought at DI. Here's the t-shirt:
3. Cut out the sleeves and cut up one side of the t-shirt (it was in a tube), cutting so as to avoid the stain on one side.

4. Carefully laid the front, back, and sleeves out on the t-shirt, then cut them out.
Front (placed so as to allow for using the hem that's already there):
Back:
Sleeve (note that I changed the shape of the sleeve slightly, so I could use the hem)

5. Sewed the shirt as per the instructions:

6. Daughter didn't like it - "too much white, Mom." Couldn't re-do it - only scraps of fabric left over from the t-shirt. Ah-ha! There was enough to add a ruffle, to cover up some of the white (also to cover up the gathers in front, which came out uneven):

7. Daughter still doesn't love it. But she didn't love anything we saw when we were shopping either. Everything we saw shopping cost at least $10, and most things were $20-$30. This cost me about $1.50 to make.
She does like it enough to say, grudgingly, "Well, I'll wear it, Mom."
For myself, it was just a reminder - a little ingenuity can sometimes go a long way.