There are some principles that I use professionally to try to understand people and their problems that seem to have some benefit for creating a character.
Draw a series of concentric cirlces on a piece of paper but leave youself lots of space between the layers.
The centre is the person and their personality traits. Their likes and dislikes, hopes and ambitions.
The next layer is their immediate family. Spouse, kids.
Next layer is important family. Parents, siblings
Next layer is work or school
The layers after that become more personal...the group of friends you go out with, your neighbours, etc.
Fill in the details that you've already decided on as best you can.
Then look for the conflict between the layers.
Generally, the inner layers are the most important to the character. You can switch them around if you like, but if you make work more important that wife then you have conflict.
If wife doesn't like parents you have conflict.
If work says you need to be squeaky clean and your son shoplifts and takes drugs then you have conflict.
If you believe the means justifies the ends but your wife doesn't then you have conflict.
If you have no-one at all in your immediate family and only have your work but you're a social person then you have conflict.
Basically, make your characters just like normal people, trying to balance the demands of different people and situations. no-one can win all the time.
Your character who is an idealist but who has to get his hands dirty to get things done and then explain what he's done to his disappointed wife while teaching his shoplifting son that he should do the right thing is interesting.
Your character who wants to do the right thing, has a wife who loves him for doing the right thing, has a son who thinks his dad is the perfect role model and emulates him, parents who think his wife is the perfect person for him, a group of friends who all support him and a job that rewards him for doing the right thing....less interesting.
The onion model can be helpful for knowing how to start when you want to write down a list of things you know about you character.....saves it becoming a random list of facts.
Craig