It could work, but the only fear i have is that your mind is so used to seeing tattoos on, say, your arms that it would also occur in your dreams. Some people wear a watch or some type of wrist band when they sleep and use that as a reality check. Most people plug their nose and try to breathe through it though. That seems to be the most common and reliable.

Also, be sure to start up a Dream Journal and read up on some induction techniques. It usually takes a few weeks for someone to get their first Lucid Dream and the biggest part is don't give up. Good luck and happy dremaing!