There Are Two Basic Methods for Turning With a Lathe
One way is to use the headstock and the rear spindle to suspend a piece of wood between the two and turn along the length of the piece of wood. This is referred to as spindle turning and is the type of woodturning that is done to create long, ornate table legs and other long wood turnings.
Some wood turners like to use a very small spindle lathe to turn ornate pens or bottle stoppers.
The Other Method
The other basic method for turning on a lathe is to forgo the use of the rear spindle and connect a piece of wood solely to the headstock with the motor. The most common type of woodturning project created in this instance is to turn wooden bowls. In this configuration, both the inside and the outside of the wooden bowl can be turned without removing the wood from the headstock. Of course, there are some considerably different techniques in bowl turning compared to spindle turning, but the basic premise is the same.
Freshly Cut Green Wood
The best way to start turning a bowl is to find a large chunk of wood that you wish to turn into a bowl. Freshly cut green wood works great for this type of woodturning because it cuts quite easily with all of the moisture in the wood. The easiest way to get started is with a blank that has been generally cut into some form of rounded shape equidistant from the center point using other tools such as a circular saw or a band saw.
Once the blank is into a generally round shape, punch a hole in the center point using an awl and then mount the blank to the chuck on the headstock, tightening it with the chuck's wood screw. The first task is to complete the rounding of the shape, for which you may want to connect the tailstock to the center point opposite the mounting point on the headstock for stability.
Position the tool rest parallel to the two center points, and about 1/8 of an inch from the highest protruding point on the stock, while rotating the piece by hand. Turn on the lathe at a low speed and begin rounding the blank using a roughing gouge until the blank is smoothly and consistently rounded to the desired diameter.
Remove the Tailstock and Re-Position the Tool
Next, remove the tailstock and re-position the tool rest so that it is parallel to the face of the blank (that was previously connected to the tailstock). Turn on the lathe slowly and begin turning the outer face of the bowl using a rounding gouge or a bowl gouge. Continue turning until the outer shape of the bowl is complete.
Then, you'll need to cut a recess into the bottom of the bowl to accommodate the bowl chuck that came with your lathe. Check the instructions on your bowl chuck to determine how deep and at what diameter to cut the recess. Once you are confident that you've cut the recess properly, remove the blank from the headstock, attach the bowl chuck to the blank and install it into the headstock. Rotate the blank by hand to make sure that it is spinning freely.
How to Hollow out the Bowl
To hollow out the bowl, position the tool rest parallel to the face of the blank and turn on the lathe so that the blank is rotating slowly.
Use two hands on a bowl gouge and gradually begin making light cuts to start hollowing out the center of the bowl. Make very gradual cuts to remove the center material, focusing on developing an inner shape to the bowl that matches the outer shape of the bowl until you have the desired, consistent thickness of wood between the inner and outer shapes.
Finally, use your bowl gouge or a scraper to create a consistent lip of the bowl, whether that be a rounded shape transitioning from the inner to the outer portions of the bowl, or more of a squared-off shape. Make very shallow cuts on the lip, as any cracks in the blank can easily catch on the edge of the cutting tool and gouge the piece.