Real name. I did a nickname at first but it felt wrong and I restarted. It’s more immersive for me if I use my real name and I know I won’t get tired of it later.
I used my RL nick Charly like in New Leaf. I thought about using an OC, but I felt it wouldn't fit somehow. However, maybe I will make another character of one of my OCs. Well see ^^
I use a nickname. If I'd use my real name, I think I'd feel like I'd have to make my character look like me.. and thus wouldn't be all that adventurous with hairstyles and colors and stuff. Using a nickname makes that easier for me.