Follow your artist's aftercare instructions.
Think about it. Dwell on it. This is repeated often because tattoos are so permanent!
Think before getting a tattoo. Will you like the design in the future? What will you do when it fades? Are you sure you want it where you put it? What will people think at a job interview? These are all things to consider before you get a tattoo. A tattoo is a big commitment and you should be prepared for the outcome, may it be good or bad.
Don't forget that if you chose to get someone's name, that person might not be around forever. They could leave, and you would have their name on your body.
Some people are against cultural appropriation, where someone takes a meaningful aspect of another's culture and uses it for fashionable reasons. If you're getting a tattoo of a traditional symbol, you should know the meaning and history of that symbol. And perhaps be prepared to defend your choice if it's not of your culture.
Laser tattoo removal is very expensive, painful, and time-consuming––in fact, much more expensive and more painful than any tattoo. In most cases though, it can completely remove tattoos. Tattoo cover-ups are cheaper, but find an artist that specializes in them. It's best to be certain about your design.
Most tattoos will need touch-ups through your life. Using sunscreen and moisturizing daily will help your tattoo look new for years. After 10-30 years, expect to need touch-ups to combat blurring. If the thought of doing this over wrinkles when you're 75 grosses you out, this could be enough of a reason to not have one.
Be extremely careful when getting Kanji characters as tattoos if you've found the design on the internet or tattoo parlour wall. You may think it means "Peace, love, harmony" but for all you know the characters could be straight off a soy sauce packet, or worse.