To set up a suitable habitat for pet tarantulas, you will need a terrarium that is at least 3 times the leg span of the tarantula in width and 1.5 times in length to provide ample space for movement. The substrate can be a mix of coconut fiber and peat moss for burrowing, and you should provide hiding spots like cork bark or half logs. A shallow water dish for drinking and maintaining humidity is essential. Temperature should be kept between 70-80°F (21-27°C) with a humidity level of around 70-80%. Decorate the habitat with fake plants or silk leaves for enrichment, and avoid using live plants that could be toxic to the tarantula. Lastly, make sure to provide proper ventilation and secure lid to prevent escapes.