Self Perception
It should be understood that how you see yourself and how other people see you is usually not the same picture. This is why soliciting advice especially from people that care about you is a good start. Ask them how your overall appearance may be helped or hurt by your choice of tattoo styles. Ask them what colors they would use if they were you.
Stay Relevant
If you are a nine to five office space type of guy whose idea of living on wild side is eating day old sushi then getting a tat of a dragon is probably not going to make sense. It's probably not consistent with your style or personality. You want to try to match both of those in your choice of potential tattoo styles. Of course this isn't a rule written in stone but rather a guideline so that you aren't wishing at a later date that the tattoo you did get wasn't there.
Design Advertising
That's right. Every tattoo style has a meaning that is broadcast out to those that see that tattoo on you. Because that is the case you want to know upfront what your tattoo's style is saying about you. Get this information from friends, people with similar tattoos, tattoo shows and etc.
By putting the research in before you get a tattoo you will be much more satisfied in the long run. And who knows? During your research for the best tattoo style for yourself you may come across a design or suggestion that is much better for you!