Here are a few things I think are helpful.
If you are not sure about who you want to do the tattoo, use instagram to find your artist! I follow hundreds of tattoo artists on instagram. I found some in my area by searching hashtags, for example I live in Delaware so I searched #delawaretattoo and found a few local artists, and they often tag other artists in the area who I work with. Really shop around for your tattoo and look at the artist’s style and skill. Look for clean linework (no shaky or uneven lines). Instagram is also awesome for finding tattoo ideas. For example, if you want to get a hummingbird tattoo, you could search #hummingbirdtattoo and see a bunch of tattoos that other people have done. If you see something you like, or a style you like, you could show it to your artist so they can get a better idea of what you want.
Be careful though about taking any painkillers before the tattoo, as they tend to make your blood thinner which could result in more bleeding and possible loss of ink (even medications like Tylenol). I know some people are ok with painkillers, but you might want to talk to your artist first.
If you are going to a good artist, you might have to make an appointment in advance. Depending on how big your piece is, you may have to wait a month or two, even more to get in with a popular artists. Some small pieces can be done in walk-ins, but you may want to just make an appointment to lock your date in.
Also, this is something I didn’t think about until I already had multiple tattoos, but if you plan on having a few tattoos, think about if there is a certain tattoo style you want. It doesn’t matter to some people, but others like to go with a tattoo style and match it for the rest of their pieces. Some styles to think about are traditional, neotraditional, black and gray realism, color realism, new school, japanese, etc. Searching all of those on google will give you an idea of the differences between each. Thinking about this ahead of time can help you decide what style you like best, so your tattoos will look similar. Then again, there are many many people with various different styles all over their bodies and that is fine too. Also, thinking about the long run can help you decide on placement. If you think you might want to add on to what you have in the future, consider placement and if there is room to expand. Or, you might think of something later that would have been better in the location of a place you already have a tattoo at.