
With the bigger tattoos, you could need to come back to have the work finished. If you do not have an idea in mind, this could take you quite a lot of time. You can look online for some concepts, or look at some of the already made designs at your local tattoo studio. If you see something that you like but you wish to be a little more creative, you can always add to the design.
You can give input as well if you need, to make sure that the design matches what you are considering. Early Celtic folks were well famous for their talents in design of jewelry, metal, and even weapons.