I really liked the shirt Lane wore in Gilmore Girls' episode 419, so I made my own version of it. It's super cute and really, really easy! Sorry about the pictures, I forgot to take real ones when I was working on it.
Start by cutting your T shirt from the top of one sleeve to the bottom of the other
Then cut the the remaining sleeve off so that you have a tank top like strap on one side
This next step is optional. I cut a big chunk off of the strapless side of my shirt so that when I added the ribbon it would be super tight. But if your shrt is already really tight, or super small then all you need to do is cut up the side.
Now you want to make sure both sides of your shirt are lined up and cut iny holes up the side. The fewer the better, so leave a bunch of space between each hole.
The last step is super easy. Just get your ribbon and thread it through the holes like your lacing a shoe. The easiest way is to do this while your wearing it so you get it the right tightness