Remember my sharpie'd shoes? Well, they kicked the bucket a while ago. I replaced them with a super comfy pair of Sanuk sandals. I don't consider them the most sustainable new pair of shoes, but I was on a tight schedule, and I hope they will last me for a very long time. The most important thing is that they are comfortable, which means that I will actually wear them, and that they aren't a waste of resources. There's only so much you can do to keep your shoes as long as possible. However, I did find more elegant ways to save two other pairs of shoes from an untimely demise.
Meet my black ballet flats. The insole was cushioned fabric, which got really nasty within the past four or so years. Originally, I wanted to buy a new pair of flats and toss these, but these have served me so well that I couldn't let go just yet. I decided to rip out the insole, and I bought a new insole. Ta-da! It fits perfectly, is ultra-comfy, and was an $8 fix. The easiest solution seems to be the best solution.
As for these guys, I bought them in Florence in 2013. Unfortunately, they are all leather (I no longer purchase leather). However, know that if you own a pair of high-quality, leather shoes, there's a high chance a cobbler will fix them up like new. And that's exactly what I did with these! Sixteen dollars later, and my shoes had restored heels and a nice polish that I had forgotten existed.
So give it a try! Take your old shoes to the cobbler, and if all seems lost, just start ripping things out. You'll learn something, one way or another. XD