Which practices are specifically advised against as unnecessary and potentially harmful first-aid actions for a mild tarantula bite?

Applying a tourniquet or attempting to suck out venom

Certain traditional, albeit misguided, first-aid techniques should be strictly avoided when dealing with the bite of a mildly venomous creature like a common black tarantula. Applying a tourniquet is inappropriate because the venom is not rapidly circulating systemically in a way that requires restricting blood flow; applying pressure can actually concentrate local tissue damage. Furthermore, attempting to suck out venom is ineffective, as the substance quickly disperses locally, and this action introduces harmful bacteria from the mouth into the wound. The focus should remain strictly on cleaning the site and managing localized swelling and pain.