Article: If your last light bulb was jammed into the socket, it may have pushed a small brass tab too far down to make proper contact with the light bulb. This tab should be raised at a 20º angle above the base of the fixture. If it is not, turn off the power and use needle nosed-pliers to pull this tab gently to the correct position. When inserting a light bulb, you should line up the threads on the socket, then turn slowly clockwise. As soon as you feel a slight resistance, stop. If you turn the light on and it flickers, turn it off again and turn only another quarter-turn clockwise.  Warning: Always make sure the lamp is unplugged or the switch is in the off position before changing a light bulb. Only do this when you are absolutely sure the power to the fixture has been turned off. Remove the light bulb from the socket if there is one present. Wearing gloves made from rubber or other non-conductive material, take a clean, dry rag or towel and rub it along the inside threads of the metal socket. You may also wipe the outside threads of the bulb base before insertion.  The cloth wipes off rust or other corrosion that has built up on the socket, reducing the chance of both burned out bulbs and a bulb jamming in the socket. Use a Scotchbrite pad or bronze wire brush if the corrosion won't come off onto a cloth. If there is too much corrosion to wipe off with a cloth, you may need to wipe them with a specialized lubricant. Only use an electrical contact cleaner or contact spray for this purpose.  There are several commercially available products called "bulb and socket lube" that can be applied to the socket or the base of a new bulb prior to installation. The product appears similar to Vaseline and greatly reduces the incidence of "sticking". Using any other substance as a lubricant carries the risk of burning out your bulb, blocking the electrical current, or jamming it in the socket. If your light bulbs only last a few weeks or months, they may be receiving too much power. Too much vibration or heat can also wear out a light bulb quickly. A long-life bulb with a slightly higher voltage than recommended for your fixtures should last longer.  In the United States, most home outlets are 120 volts. Use a "long life" bulb that can handle 130 volts. In the European Union and most other European countries, the standard varies between 220 and 240 volts. Standards vary widely in the rest of the world. If you're not sure what voltage your outlets use, see this list by country and these images of outlet types.

What is a summary?
Pull the brass tab at the base of the socket to the correct position. Insert new light bulbs gently. Use a clean, dry cloth to wipe the inside of the socket. Use an electrical contact cleaner to wipe off heavier corrosion. Use bulbs intended for a higher voltage if your light bulbs burn out frequently.