One of my own techniques I like to use for creating interesting characters is to map out their 10 closest relationships through life. I like to call the character with all 10 close relationships complete my 2D character and any of the 10 characters I don't plan on doing the same with (going into their 10 closest relationships) my 1D characters. So for example I create a character named Bob, I will write the most 10 important people in Bobs background, usually family members, close friends, father figures, bosses, enemies. So Bob is my 2D character and I will have 10 more 1Ds. Then I'll chose one of the 1D characters and write their 10 relationships. Some of their characters will be the same as Bob and there will also be some new characters but even the same characters will have different relationships because of their different personalities obviously. So the reason I wanted to develop a strategy along these lines is because whilst reading I realised something about my own taste. I prefered it when a character would think back to a scene with someone close to them and show a little more of their relationship piece by piece. Until you sort of get a feel for why this character is who he is and where he has come from. I often feel like the traumatic event is a bit of a cliche and quick fix compared to this. In my opinion finding out how someones father was neglecting them through their childhood through anecdotes and character thoughts is much more satisfying and relatable than "my father beat me half to death". This is a hell of a lot of work though, honestly I'm spending about a month just on character development alone. I'm wondering if the method is really worth it, are there quicker ways and how complex should I make the background relationships really? I sometimes worry that the relationship hasn't taken enough twist and turns in the characters background for it to be complex and realistic enough. The other problem I have is it's awfully hard to figure out their relationships together without ever developing the 1D characters, because I don't know who they are. Writing something like Bob had a bad relationship with his mother feels sort of weird when I don't even really know who Bobs mother is yet.
I'm not entirely sure what you're asking here -- I want to say to do what works for you. I also think that you can't ever know your characters too well -- that is, the more you know about them, the better. It will show in your writing and it will be second nature to have them do or say certain things or interact with other characters in a believable manner. If your 10 relationship technique works for you, that's great. Keep doing it, then. But if you feel it's become a hinderance or not worth it, then stop. You can always write scenes with the characters you want to know more about -- not necessarily map out their relationships, but put them at a lunch table together, or telling another character his mother died, or coming home from work, or after being fired, or whatever. You don't have to use the scene in your story, just use it to develop the character. At the end of your post you seem to be saying that your technique isn't working for you. You could map out relationships with other characters or you could just kind of talk with them. In my stories, I found out who my character's friends and family members were just by having scenes with them. They went to their mother's house for dinner. Who else was there? Oh yeah, his sister and her husband. And also his niece. Turned out his nephew wasn't there, but did exist. Where was he? Oh, he was at his first school dance. That told me roughly how old he was, and therefore how old the sister was, etc. But my character was going to be seeing the nephew next week. That was important because my MC doesn't have any kids. Oh, but you know what? He'd really like some. That's why he likes seeing his nephew and niece. Later in the dinner his mother mentioned that she was upset the MC's brother wasn't there. (Oh -- I didn't realize until now he had a brother!) Why isn't he there? Oh, because he's kind of a loser. What made him be that way? The MC is annoyed with him. Just because his dad left when they were kids didn't mean that the brother had to throw his life away. MC and his sister turned out just fine. That kind of thing.
I like that. It's almost like a nice blend of outlining/discovery writing together. I guess I was asking for tips on strengthening in the method I was trying to explain but also anyone else methods are welcome because it seems most people like to use a mixture of them together anyway (and I always find them helpful, like I said I really like the once you've explained).