Unless you want to be a lifeguard, your entire torso should be covered up while at work. You're not going to be wearing crop tops and low-cut jeans in a professional space, so no one will be able to see a tattoo on your hip. The only people who will know about your body art are the people that you tell.
If you get a tattoo anywhere on your back, it'll be hidden from the world. Shirts may go low in the front, but they don't tend to go low in the back. As long as you aren't stripping down for your coworkers, they'll never see your gorgeous tat.
3. Back of Neck
This one is a little more risky, but for most people it will work. If you have long hair that you're allowed to wear down at work, then it'll cover up the tattoo. However, if you're required to push it back into a ponytail or if you prefer to maintain a pixie cut, you should find another spot for your ink.
4. Upper Arm
If you get a tattoo high up on your arm, you can easily cover it with a teeshirt. Just don't get an entire sleeve done, because then you'll be stuck wearing long sleeves for the rest of your career. Unless, of course, you find a job that's accepting of who you are.
The top of your foot is actually a pretty private place. If you wear socks and sneakers, no one will see it. If you wear heels, you just need to wear leggings or thick stockings so that no one will notice the tattoo. It's a pretty safe spot.
Even if you get a job that involves being outdoors and wearing shorts, you won't be wearing ones that are so short that they expose your whole thigh. As long as you get a tattoo in a spot that will always be covered by your clothing, there's no problem.
Here's another spot that no one will ever be able to see unless you lift up your shirt to show them. If you're not comfortable getting tattooed on your ribcage, you can also get it done on your spine, your stomach, or even a spot on your chest that won't be visible when you wear a low-cut shirt. Believe it or not, you have a pretty big range of choices, so pick what feels best for you.