Chain (using a crochet hook)
This technique is often used alongside the Provisional Cast-On technique when wishing to start off via crocheted chain.
Make a slip knot and insert your crochet hook. Continue on with the hook, catching the standing yarn "up from under," then draw it through the slip knot (picture above). Once the new loop is on your crochet hook, continue to catch the standing yarn in the same manner and pull it through the previous stitch. This will make a "chain".
Continue until you have either the desired number of stitches to the chain or the required amount of stitches.
For the Provincial Cast-On with crochet chain.
After you have the crocheted chain, you have to slide the correct loop of that chain onto your knitting needle. It's fairly easy to do, but it's also fairly easy to make a mistake and catch the wrong loop. If you do catch the wrong loop, the provisional casting-on won't "unzip." That's actually an easy problem to fix with a quick snip from a pair of SHARP embroidery scissors (cut the provisional cast-on of course, not the first row of loops). But if you want to be able to "unzip" with the pros, read on.