My sensei gave a tameshigiri cutting demo once, and his sword looked to be in rough shape in the handle dept. He acknowledged it, and made the comment that he needed to get it "professionally done somewhere". I told him that I could try it, that I knew how. He was confident enough in letting me take his sword home.
I got the thing home, took all the ito off the handle, washed it, ironed it, and wrapped it. I returned it to him, and he was very pleased. Other Sensei, and high ranking students in the Dojo also approached me for tsukamaki work. From then on I was wrapping sword handles in exchange for my training.