I saw this method of sewing your bootleg jeans into skinny jeans a long time ago on Maybe Matilda. I never had the desire or need to use it, until now.
My body's all changed and changing after pregnancy (everything is going back differently). As a result, a pair of jeans that once fit me fine, no longer fit. I gave them to my sister, telling her I could skinnify them so she could wear them with boots. Since I was working on her pants, I decided to do a pair of pants for myself too.
These pictures are mid-project to show the before-after.
I have since finished the pants, hemmed them, and worn them to work. I'll try to update this post with a full-on after shot. But I might never do it, just because my free time to blog is next to non-existant these days.
Basically, if you can sew a straight line, this project is perfect for you. It's pretty simple.
Here's the tutorial I used for making your jeans skinny.
Here's the tutorial I used for hemming jeans.
Go, therefore, and skinnify your own pants.