Since this time around people have created characters and sometimes it's hard to "figure them out" I'm going to be posting some things I've found on tumblr (or even here) that'll help you guys along. And since these are going to be asking "intimate questions" about your characters it's probably best that they're kept in private worlds so you don't expose all of your secrets. You can choose a few to broadcast, but let's keep these under wraps.
1: What does their bedroom look like?
2: Do they have any daily rituals?
3: Do they exercise, and if so, what do they do? How often?
4: What would they do if they needed to make dinner but the kitchen was busy?
5: Cleanliness habits (personal, workspace, etc.)
6: Eating habits and sample daily menu
7: Favorite way to waste time and feelings surrounding wasting time
8: Favorite indulgence and feelings surrounding indulging
9: Makeup?
10: Neuroses? Do they recognize them as such?
11: Intellectual pursuits?
12: Favorite book genre?
13: Sexual Orientation? And, regardless of own orientation, thoughts on sexual orientation in general?
14: Physical abnormalities? (Both visible and not, including injuries/disabilities, long-term illnesses, food-intolerances, etc.)
15: Biggest and smallest short term goal?
16: Biggest and smallest long term goal?
17: Preferred mode of dress and rituals surrounding dress
18: Favorite beverage?
19: What do they think about before falling asleep at night?
20: Childhood illnesses? Any interesting stories behind them?
21: Turn-ons? Turn-offs?
22: Given a blank piece of paper, a pencil, and nothing to do, what would happen?
23: How organized are they? How does this organization/disorganization manifest in their everyday life?
24: Is there one subject of study that they excel at? Or do they even care about intellectual pursuits at all?
25: How do they see themselves 5 years from today?
26: Do they have any plans for the future? Any contingency plans if things don’t workout?
27: What is their biggest regret?
28: Who do they see as their best friend? Their worst enemy?
29: Reaction to sudden extrapersonal disaster (eg The house is on fire! What do they do?)
30: Reaction to sudden intrapersonal disaster (eg close family member suddenly dies)
31: Most prized possession?
32: Thoughts on material possessions in general?
33: Concept of home and family?
34: Thoughts on privacy? (Are they a private person, or are they prone to ‘TMI’?)
35: What activities do they enjoy, but consider to be a waste of time?
36: What makes them feel guilty?
37: Are they more analytical or more emotional in their decision-making?
38: What recharges them when they’re feeling drained?
39: Would you say that they have a superiority-complex? Inferiority-complex?
40: How misanthropic are they?
41: Hobbies?
42: How far did they get in formal education? What are their views on formal education vs self-education?
43: Religion?
44: Superstitions or views on the occult?
45: Do they express their thoughts through words or deeds?
46: If they were to fall in love, who (or what) is their ideal?
47: How do they express love?
48: If this person were to get into a fist fight, what is their fighting style like?
49: Is this person afraid of dying? Why or why not?
I hope this will help you. If you see anything like this, send it my way and I'll post it! Or you could post it yourself. I'm just very picky about format.
P.S. This'll help with actual characters as well. Since I'm going through this and going "Hunh, didn't know that about myself". Everyone could benefit from something like this. Just make sure to keep it available to only yourself.