What about tattoos and piercings?

A non-traditional appearance can be much more of an issue overseas than in most Western countries.  Conformance to certain conservative values is important in some countries, and certainly for professional and/or teaching jobs in almost all countries. 

In Western culture, we tend to pride ourselves on the "rebel billionaire" look, and we know that dress and appearance really don't measure the quality of our character.  But in many other cultures appearance is paramount.

A Cultural Lesson

In Korea, just as one example, a common saying is, "The first impression is everything."  Appearances are critical in many cultures.  When the author lived in Africa he would sometimes be surprised to see a man come out of his mud hut wearing a three-piece suit!

Dress nicely and professionally.  It's not difficult and will enhance your opportunities.

Our ideals are often not theirs.  Play along, do what is required.  Wear the slacks and tie.  It is the gateway to so much more.

Tattoos and More

Keep them out of sight.  In some cultures, tattoos are symbols of the yakuza or mafia.  Yes, even in Thailand many local people have tattoos, but they will keep them out of sight when interviewing for a job.  As a foreigner, in most cultures/countries you can expect to be closely observed, judged, commented on and just generally be the butt of gossip.  Get used to it, understand it, and deal with it appropriately.

For many people showing such things off is a matter of pride and principle.  They feel they should be accepted for who and what they are.  Yeah, but . . . other cultures don't often have the same idea.  In their country, they would like you to conform to their ideals.  You will, I promise, limit your career and opportunities [in many countries] if you are not discreet. 

Play along, it is the gateway to so much more.