1. Patience The first tip is patience. Do not rush into a design decision. Be sure that the design you settle on meets all of the emotional requirements you will place on your first tattoo. Remember, painful surgery or cover-ups are the only ways to get rid of a tattoo once you have it and both options take a lot of money and thought to implement.
2. Consistency Think of a theme. Here I do not mean that you need one, but you should consider it early if you decide that you do what to embrace a theme. If you get a permanent piece of art that doesn't fit your theme idea, it will either be out of place on your body in contrast to future tattoos or you are back to cover-ups or surgery. Some people only get one tattoo. That is fine, of course, but most people that get ink once get the fever (like I did) and plan out many return trips to their favorite artist to balance out the tattoos they already have.
3. Your Artist Choose your artist well. Be sure to shop around for someone that has consistently great art. All artists will have a portfolio of their own designs and final tattoos in their parlors. If they do not, avoid them!
4. Composition and Placement Positioning is a major factor. Be thinking about if you want other tattoos and how the one that you ill get first will interact with tattoos you may get later. Certain areas of your body will be much more sensitive than others. This can be an attraction for some as well as a turn of for others. Know you body's limits and think about where you are going to have your design placed. Test placing is standard. Pay close attention to this step. Don't let an artist rush you through it (although usually they are quite helpful with this step.) Again, this will be there permanently, so do not take this step lightly.
5. Personalize Make sure you design says something emotionally to you. Do not just get a cartoon or a heart with a name on it on a whim. Take out a piece of paper and write down all of your favorite things, artistic or otherwise, and try to narrow down what you are attached to personally. I am a Tibetan music specialist and I have a love for old bad monster movies and therefore I have a theme of Tibetan art featuring Tibetan mythological creatures, for instance.
Back to the artist and the design: some artists specialize in a particular type of art. Seek these artists out if you have a theme or special style in mind. In my case, I found a great artist that studied Tibetan art informally. His work converting my designs to flash was superb and I am very proud of my tattoos because of it (as is he, for that matter.) Let me say again, shop around and do not rush into anything.