I have 7, the one thing is that your sketch will not look exactly like that once done, if you have a good tattoo artist he will explain to you that your vision while great on paper will likely not work o you, your skin is a very different canvas and placement and skin quality can greatly affect your design, so he will rework your work based on what he knows will work best and make you happy, not just on that day but for the next YEARS to come.

Now if the artist is not that great he will likely tattoo anything you want him to anywhere you want to.

Choosing the right artist is VERY important and establishing a good relationship and having an understanding of what works, what doesn't is a must.