A few years ago I took some photos of how I hold the yarn for knitting, to remind my friends what I had taught them during a lesson. This is
only one way to do it, but it works well for me. Perhaps it will work for you too!
#1 – drap the yarn over the right pinkie finger from back to front
#2 – turn the right hand so the palm faces down
#3 – position the right index finger so it comes up under the working yarn
#3 – lift the right index finger to tension the working yarn
#4 – gently grasp the yarn with the right hand, letting it slip through the hand to the index finger as needed (feline assistance is optional).
If you are knitting with slippery yarn, you may wish to wrap it around your pinkie first and then around your ring finger. Or try wrapping the yarn around your pinkie more than once. Experiment and do what works best for you!