Although using a flash is often the easiest way to light a photograph, it is rarely the best way to light pottery when you want good pictures. (The below information is also useful when photographing paintings, drawings, needlecrafts, and other creative works.**)
Light will reflect back from most pottery surfaces. In order to eliminate or reduce glare, set your lighting source(s) set at a 45° angle to your work. This will give the best and most even lighting. You may need to bounce your light off of a white screen or other reflective surface before it hits the pot, or adjust the angle of the light.
If you have a heavily textured surface, you may have problems with shadows developing. Dual-source lighting can help with this problem, but you may also need to diffuse your light. You can do this by passing the light through cheesecloth before it reaches the artwork. Note: Cheesecloth must be away from the bulb and light fixture! Use a separate frame and stand to hold the stretched cheesecloth. (A large embroidery hoop or painting stretchers can be helpful in stretching the cheesecloth.)
Remember, photoflood lights generate tremendous amounts of heat; use good sense. Do not allow combustible material to rest against either the bulb or the fixture, especially while in use. Do not trap the heat by using a reflector shield pointing downwards. Keep the lamps on only as long as necessary. Never leave burning photofloods unattended. Do not use photofloods with any equipment, including sockets, electrical outlets and extension cords, which are not rated to handle the wattage.
As you set up your lighting prior to shooting film, be aware of the diameter of the light's beam. As a general rule, the larger the object, the broader a beam you want. You may also, especially if shooting sculpture or reference photos, want to employ small, narrow-beamed highlighting spotlights to bring out or emphasize a particular area.
** Tip: If you want to photograph something that is under glass such as a watercolor, it works best if you first remove the glass from the frame. Replace the glass after you have the photograph(s) you want.