Controlling humidity in most cases will be low maintenance when the habitat is selected/designed correctly for the species being housed in it. Have the correct habitat in your possession and setup for several days at a minimum ( preferably a week ), so you have time to make the major environmental adjustments before the animal is placed in it. Some species are very susceptible to severe health issues or even death if housed incorrectly.
Snakes a whole do not require a large amount of ventilation in their habitats. This is to your advantage when it comes to humidity control. The easiest way to control the humidity level is to control the airflow. I design my own habitats with that in mind. Vents are located close to the floor of the habitat with another vent at the top that is closed off most of the time. Keeping the vents located low in the habitat helps to prevent the warmer, moist air near the top of the habitat from escaping. I also add power ventilation using small low vibration computer case fans. When the humidity is higher in the house during the summer, the extra airflow from those fans keeps the humidity in line for the non-tropical snakes like the Bullsnake.
Controlling the airflow alone may not allow you to reach the desired humidity level. In those cases, the addition of a moist hide, or simply a flower pot tray with moist sphagnum moss on it will likely solve your issue. This is often helpful during shedding as long as you do not allow the humidity to get too high for the species. I have even placed slightly damp pillowcases in habitats that some snake used as hides during part of the shedding process. Depending on the humidity in the room where the snakes are housed, you may even have to mist the habitat or purchase one of the humidifiers that are commonly available. Correctly set up, keeping the humidity at correct levels for the captive, should be painless for both you and the animal.