Some of the common ways are to use under tank heaters. that only cover one half of the cage and watch how much heat is generated by the lamps I know my pet store sold me a bulb that is way to much for my snake at basking temps. I'm able to get a floor temp gradient of 12 degrees or better with an under tank heater in only half of the cage. We do need to know a bit more about your snake cage setup before we can give you any tips that will benifit you.
Snakes? I just like to teraform!