The white American infatuation with Mexican stuff, if not Mexicans themselves, has been an object of fascination to me for a number of years, and I've become quite an expert. Most white people gravitate towards Dia de los Muertos stuff (kitschy! edgy! vaguely but not uncomfortably spiritual!). It's not exactly perplexing; white people love making vague statements about the wonderfulness of having a positive attitude towards death and so forth. Plus, skulls are cool. I'm assuming this is the reason why a Latino friend of mine was asked if he was going to participate in a "Dia de los Muertos Zombie Walk", logically scheduled to coordinate with Cinco de Mayo celebrations. He did not react well, suffice to say. Such a wet blanket.
Despite your best efforts, your earnest and totally misguided offensive appropriation can fade from memory with time. Luckily, there's a way around this. For generations, people have covered their flesh in stereotypical depictions of other human beings and their cultures, and it has yet to go out of vogue. A couple of sugar skulls on your upper arms will lend an exotic vibe to any WASP, and, what with the overwhelming current of xenophobia and racism in today's society, no actual Latin@ is likely to feel comfortable challenging you on it. If they do, make sure to tell them how much you loooooove their culture and it means sooooo much to you. They'll look like ungrateful meanyheads and will be forced to back off. If all else fails, ask them how they celebrated the last Day of the Dead. No doubt they'll say something boring about visiting the graves of their dead family members or something, whereas you made up your face like a Sylvia Ji painting, baked some authentic Mexican bread using authentic internet recipes, and built a shrine to Frida Kahlo. It's clear who the winner is.
Not feeling this Mexican stuff? Get a gypsy or geisha, or maybe an American Indian. Don't let anybody tell you this is offensive. After all, such designs have been used for years, and tattoos are all about your feelings, not about centuries of ongoing marginalization and genocide. It is your right as a privileged person to have cartoonish depictions of other human beings permanently marked on your body. Be sure to attach lots of meaning to your tattoos, because intent is everything, and criticism of your tattoos is nothing less than a personal attack. If all else fails, make a poorly reasoned argument about how the visibly tattooed also face discrimination in our society, and maybe say something about "my body, my choice!" They'll be dazzled by this irrefutable logic, especially if you get a bunch of your friends to say it too.
Good luck, friends. Remember, the kyriarchy is nothing without people like you.