On most motion sensor lights there is a switch to adjust the range and duration the lights will be on. There is also a switch on most motion sensor lights which will turn off the motion sensor and keep the lights on permanently. However, if this is going to be done, it is important to make sure the lights are wired directly into the house's electrical system, as some run off batteries and the batteries will run out very quickly if these lights are left on the entire time.
As the motion sensors on these lights can be adjusted to aim in different directions, point the motion sensor at something that is always moving. If you live near a busy street or corner, aim the motion sensor at the street. The constant passing of traffic or pedestrians will keep the light on. If you have a fountain in your front yard, aim the motion sensor light at that, as the moving water will be enough to trip the motion sensor and keep the light on.
By wiring the lights to a switch inside the house itself, the motion sensor lights can be turned on and off like a light switch from inside. This wiring is rather simple to do with some simple electrical knowledge. It can be accomplished by running the wires from the lights directly to a fuse, which connects to the switch inside the house. It is probably best to place this switch in an area that is not by other lights, so this switch isn't constantly turned on and off by people trying to turn on other lights inside the house.