The best way is with one, or two in colder areas, UTH. ALWAYS controlled by a thermostat or dimmer at least. If you have the UTH on a thermostat, you often have to have the setting on the stat much higher than the desired temp to get where you need it.

If you don't have it controlled, you need to get something ASAP. Measure temps at the bottom of the tank on the glass right above the UTH and aim to get THAT to read around 93-94. Then get the temp on the substrate above that about 1-2 degrees lower.

If you can't keep the room your snake(s) is in at 80-82 degrees year round, then a second UTH on a second t-stat is recommended over lamps. Lamps should only be used to boost ambient air temps in the tank.