I was making flowers as opposed to poms which would be fluffy on all sides, so I used green flower wire. You could also just use string or ribbon if you were making poms.
Gather at least 6 pieces of tissue paper. You can add more to make it fluffier. Then accordion fold the tissue paper and use your wire in the middle to hold it together.
Once you have it tied off in the middle, you will want to cut each end of the tissue paper in the method you desire (more on this in a minute) and then carefully fan out each side, fluffing up each piece of tissue paper.
Here are some common ways to cut the ends and the results:
You could also make smaller versions of these to use as bows for gift wrapping!