Here are a few examples of tube or cylinder beads I made with fimo (polymer) clay:
They are, as you may have guessed, very easy to make. It just takes fimo clay (colour of your choice) and something to “build” your tube around (a big needle, a small metal cylinder… anything that matches the diameter of the hole you want in your beads and that you’ll be able to put in the oven when baking your clay).
Insert the needle or cylinder inside the polymer clay (be careful to air bubbles and holes, if there are some the clay is likely to be torn at the next step):
Roll the clay around the needle (on a flat surface… the table for example!) until you reach the diameter you want your beads to be, cut the exceeding clay at the extremities of the needle (you may have to do it more than once if you use a large amount of clay with a short needle or want to achieve a small diameter for your beads):
Use a blade to cut the clay around the needle and put everything in the oven (leave the needle inside the clay, of course). If you have (like me) a very convenient stand for baking your beads, it’s very easy. If you don’t you can build a small stand out of aluminium foil so that your beads don’t rest on a flat surface (if they do they’re likely to have a "flat side" after the baking!)