I like to wrap my yarn into balls, then put them into this glass pitcher I have to keep the yarn clean and contained while I work with it, which has been just fine, but sometimes I have a ball too big to fit inside the opening and I really don't like cutting the yarn and rejoining later.
I searched videos on youtube to see what I could do to make a center-pull ball and found a bunch of variations on rolling one by hand. I like this one on wrapping around a cardboard tube.
I used a pen tube so the hole in the middle was smaller and the ball wasn't too big when it was done. after I ran the yarn through the tube I pushed the tip of the pen back in just enough to hold the yarn in place while I wrapped the ball.
it came out a little egg shaped as I wrapped, but once it was off the tube I was able to round it out.