Final answer:
The techniques used to locate a vein include warming the area, tapping the vein, and having the patient clench their fist. Applying ice and massaging the vein can also be helpful.
Step-by-step explanation:
The techniques used by the phlebotomist to locate a vein include warming the area, tapping the vein, and having the patient clench their fist. These techniques help to dilate the blood vessels and make the veins more visible and easier to access. Another technique that can be used is applying ice to the area, which causes vasoconstriction and helps to bring the veins closer to the surface. Massaging the vein can also help to make it more prominent.