Try to stay still, if the position you're in is uncomfortable, tell the artist that you need to move.

However, you will get tiny spams, and that is normal.

Dress for it : something comfy, you're going to stay in the same position for hours, and think that the artist need access to the area being tattooed. (My tattoo artist also recommended me to wear black clothes)

In USA-Canada (I think) : tip, between 20%-25%. It's not necessary in Europe, for what I know, but a bit of research before going to another country to get tattooed can't hurt ^^

3 parts finally oops