Originating from a warm climate, leopard geckos need a constant supply of heat to help them regulate their body temperature. It is best to create a heat gradient by having a warm and a cool side to the enclosure, allowing them to move between the two and control their own temperature.
You can heat your enclosure a variety of ways; there is not a one size fits all solution. There are just too many variables, from the temperatures and draftiness in your home, to the enclosure location in your home, to the type of enclosure you are using, etc.
One of the ways people find best is to use a under tank heating device or "UTH", be it a traditional UTH, Flexwatt, heat rope, or other. You can also use Ceramic Heat Emitters, Radiant Heat Panels and Heat Bulbs in reflector lamps to name a few. In some cases you may need to use a combination of heating devices to achieve ideal temperatures. Also, it is my opinion that ALL heating devices should be used in conjunction with a thermostat or rheostat. With a little trial and error you should be able to maintain your temperatures in the ideal ranges.
Ideal temperature ranges consist of a hot side of the tank between 87o F and 92o F with a cool side between 70o F and 78o F.
Be aware that albinos are sensitive to bright lights, and may not do well with an overhead lamp. Juveniles should be kept away from light for at least 2 weeks.