The two most common ways are Continental and "English", or throwing.
With Continental, the yarn is held in the left hand, and the right needle slides through the loop and 'grabs' the yarn and pulls it through. Crocheters tend to prefer this style since they're used to holding the yarn in the left hand.
The English, or throwing, method has the yarn in the right hand. The right needle is inserted into the loop, and the yarn is wrapped (or thrown if your fast, I imagine) around the right tip and pulled through. Usually the yarn is wrapped around the right hand in such a way that you don't have to actually hold it between your fingertips, though that is how the whole process is taught.
Some people plant the left needle on their leg and work the right needle.
There are other methods out there, some unique to the individual, but all have the same results, thankfully.
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