I am 23 years old and I have done tattoo last year. I will admit that doing the tattoo is a little bit painful and you must have the strength and courage to tolerate the pain. You can engage yourself by doing something else as like listening to music, reading the books or watching anything in your phone. You must calm your mind and stay relaxed. Do not drink alcohol or take drugs while entering the tattoo studio. You should eat enough food or else you might feel weak and drained. Keep yourself hydrated.
Getting tattoos from a proficient and experienced artist would reduce pain largely. People can also try a few other effective tactics such as chewing gums, squeezing stress ball, taking deep breaths, asking for frequent breaks, etc. Eating a full meal before session would also help because penetrating skin with needles on an empty stomach trigger risks of passing out.