Have several.
Before: have them sketch a rough drawing of it or print it from online. DO NOT NOT NOT GO CHEAP! I tell people that all the time, they dont listen and bitch when their tattoo 'chaps' or they get an infection and it fucks their tattoo up. You really do pay for quality with this. If its big, break into sections. Your artist, body, and wallet will thank you.
Also scan the parlor. If it looks run down, walk out. Ask what ink the artist uses. Google it to check for recalls. Not all artists catch recalls. Check the artist previous work. He/she should have a book of their work. If not, walk out.
If it is a 3-D tattoo (if you dont know what that is, it probably isnt one.) Get the best damn artist you can find. Even talented artist can fuck those up (my 3-d that is the size of my shoulder ran $4000 because they are hard. At the same time, my 3d on my forearm only ran 600.)
During: do not take pain relievers, drink, or anything to avoid the pain. I have a high pain threshold so it has never been a problem for me, but if it hurts, inform your artist. They can ho slower or gentler. Do not try your own way to avoid it. You will hurt yourself, bad. Your tattoo will be bloody. It will be hard to see. Ask your artist to stop every once and a while, clean the blood and check how it is coming. This is your chance to fix any errors.
After: aquaphor for babies. Best after cream I've ever used. My tattoos still look brand new after 2 years from that miracle cream. Avoid the sun for a month and avoid pools. You will ruin the color. Color fades and black turns grey if you do either of those.
If you want to hide it. Back. Get your back done. Shoulders appear in tank tops. Back will barely show. Or chest so your lady can see it when yall do the nasty and it is still hidden.
If you have any questions, PM me. I dont mind.