For example do you say to yourself “I need to do the dishes now!” or “You need to do the dishes now!”?
First person.
Both. And sometimes I even go regal on my own ass and refer to myself as “we”.
If I’m trying to get myself to do something, 2nd. If I’m narrating to myself or reminding, 1st.
Q.E.D. resents the omission in the OP. No, Q.E.D. doesn’t like that one bit.
Forgive my ignorance, but I do not understand.
Never mind, on further reflection I do. :smack:
Some people (no, I’m not really one of them) might refer to themselves in the third person.
Q.E.D. eschews the first and second persons and goes with the third.
I use both 1st and 2nd in internal monologues, with no consistency. I only refer to myself in the 3rd person out loud in attempts to annoy other people. 
It depends. When I’m being self-critical, it’s almost always second person. Otherwise, first person.
Most often in the second person, but occasionally the first.
And like eleanorigby, frequently the regal “we”.
I seem to scold myself more often in the second person, and feel more neutral using the first person.
Ex1: “Oh, you fool, now look what you’ve done! Come on, then, let’s clean it up.”
Ex2: “What was I doing again? And where am I?”
The second person if I’m being self-critical, the first if I’m laying out my plans for the day.
Huh. I never noticed that before, but you’re absolutely right. (For me, I mean. I bet you already knew you were right about you.)
Groo the Wanderer strode the earth like an angry god, his piteous minions scattering in fear at the sight of his visage. Would he be merciful today and spare these wretched peoples’ lives? Perhaps after dinner, he though, but first he had to go check the SDMB.
Heh. Me too. “I’m such a genius for managing to do that huge pile of laundry!” “You idiot! You’re late for work again!”
That way, I get all the credit and none of the blame.
Both. There’s not much consistency, but second person tends to get associated with the emotional side of a decision, and first person with the logical side.
I use first and second fairly interchangeably, but I tend also to praise in the first person and criticize in the second.
One has considered this, and has come to the conclusion that:
I don’t use either. I tend to say in my head : “Must do this. Gotta do that. Don’t forget those.” If I ever refer to myself directly, I cannot bring to mind how I phrase it.
Both and also first person plural. It is not uncommon for me to think in terms of “we need to get our big old butt up and moving”
First person if I’m making a judgment about myself. Second person if I’m reminding myself of something or psyching myself up. And “we” if I’m having conflicting emotions, because it’s like two people (both myself) arguing with each other.
I wonder if Bob Dole’s inner monologue is in third person. Bob Dole’s a friend of the tobacco industry. Bob Dole likes your style. Bob Dole. Bob Dole. Bob Dole!