There are plenty of websites around that will direct you to decent tattoo templates to use, some are popular others unique the choice of tattoo designs out there is literally endless, this hinders many from even getting a tattoo. It can get annoying looking for that perfect tattoo after a while with the amount of tattoo websites.
Some times the best tattoo art is a design you can draw for yourself (if you can draw). Others will say its a popular tattoo that famous people have. I personally think it should be a well researched decision on whatever your idea is look it up on the internet the meaning the history whatever you can learn will give you a better guide if it is the right choice for you.
Maybe your choice on a certain tattoo design is to signify a change, person or milestone in your life this is what alot of people do, "they dedicate it to something" so it has deep meaning to the person which in turn makes the person confident, proud and happy with there piece of art.
Other times people want new art that is unique in design that has never before seen, preferably this would be my choice as i like to be different. If this is the same way you feel then researching the meaning of the design would not matter as much, it will be just based on whether you like the tattoo design or not simple as that in my opinion.