So useful character traits to consider then could include:-
- Being a Liar/Being Honest (the latter could cause as much trouble as the former and the potential for comedy is here too);
- Stubbornness/Being Flexible;
- Being Unfriendly/Being Sociable;
- Being Prejudiced/Being Open.
There are of course many more traits than these and practically every trait has its opposite flaw/virtue which could also be used.
Questions to ask yourself when using these:-
- How did the character develop this flaw/virtue?
- Do they see it as a flaw or virtue? Are they right about this?
- How do others around the character react to them and their flaw/virtue?
- What are their society's expectations?
- Does the character change - for better or worse?