Definitely depends on the job. If you never want to ascend to a higher station in life, or you work in a tattoo parlor, let it all hang out. I have never been a fan of piercings, but I have a full tattoo sleeve and several others. I always, always, always, wear long sleeve shirts at work. The truth is that body modification is not as widely accepted as some would like to believe. I still get dirty looks to this day. Since I don't carry around a copy of my resume, this is all many people need to form a first impression.
If you're wrenching on my motorcycle, I would expect you to have tats. If I'm going to the doctor's office, I should see nice white lab coats and nothing else.