While at a GoodWill store (we were looking for shelves to help our new house become a home) I happened to pick up some sweaters. I had heard that you could unravel them to harvest the yarn for future projects. I had also heard that you can find really nice yarn/sweaters for next to nothing at charity shops like GoodWill.
I bought 3 sweaters the cotton variety took them home, washed them of course and started away.
"How hard could it be to unravel a sweater"
I then searched the internet for tutorials. I found a great one HERE that included pictures and step by step instructions.
Once I followed that I was able to salvage most of the other 2 sweaters. I got a ton of yarn and though the process is time consuming and you get littered with little yarn bits It was worth it to get high quality yarn for next to nothing.
I even used some of the yarn to make the flower on my free hat pattern.
I encourage others to repurpose yarn this way. It helps give old sweaters a new home. Just read the instructions first.