If you are using a spinning wheel to create two-ply yarn, you need to transfer your singles to a kate before you can ply. Before you start plying on a wheel, practice to ensure that you can make the wheel move easily to the left.
Set the wheel up as if you were going to spin. Place the kate on your fiber-hand side.
Pull up the ends of the two singles and attach them to the leader by separating the leader and inserting the ends of the singles in between.
With the palm of your fiber hand facing you, place one single over your thumb and the other over your index finger. Curl your other fingers shut over both of the singles.
Try to keep an even tension on both singles.
Start the wheel with your spinning hand, pushing it to the left.
Once you have started the wheel, take the middle finger of your spinning hand and insert it from underneath the V that was formed by the singles that are close to the orifice of the wheel.
This separates the two singles and leaves your index finger and thumb free to pinch, pull, and guide the twist up the singles.
If you need to let go with one hand, you should let go with the spinning hand. You will still have the singles in order, as long as you do not let go with the fiber hand.
Move the spinning hand (here, the left hand) back toward the fiber hand, as evenly as possible. Guide the twist back with your fingers.
Use your fingers to smooth out any rough areas.
Move your spinning hand all the way back to the fiber hand.
Pinch off the singles and pull them forward toward the wheel.
Adjust the pressure on the singles in your fiber hand so that the yarns can move smoothly forward.
Keep the fiber hand steady.
Think of it as being glued in place. If you move this hand, the yarns can lose their tension and become tangled. Moving your fiber hand can also cause the bobbins to jerk back and forth.
When you have fed all of the yarn into the orifice, start the process over again.
Make sure the bobbin fills up evenly. Move the yarn from hook to hook more often than you do when you spin singles. Plying takes a lot less time than spinning.