You know, I've always found it hard to find examples of 3-D, well rounded, believable characters.
Until I tore my eyes away from the internet that was!
To my utter disbelief, there was this person, female I think, in the kitchen. When I realised this wasn't a perfectly rendered human scale model, I surmised that it must be a real, actual, functioning human being. Then the female told me that Tea would be ready in ten minutes and to stay out of the kitchen if I'm not doing anything.
Extraordinary!
What I'm trying to say, in a roundabout, snarky, somewhat condescending, vaguely sarcastic and hopefully humourous way is that a good character seems real.
And real people exist everywhere, unless you live alone on a small pacific island, or are the subject of a Truman Show like thing where only a few moments ago, millions of people watched you log onto a Pokémon fansite and ask a question about character creation.
Oh crap, I forgot we aren't supposed to say anything to you about the show :x
Aaaaaaaanyway...
Look for examples in your real life, I'm sure you've known an arrogant jerk in your time, or a really up-tight person who thinks they're better, or a really nice person, or someone who just doesn't seem to care, or a bully. Need I go on? Think of a character archetype to fit your situation and think about how that character would react in certain situations. If faced with adversity, would they rise to it? Or shrink away? If faced with a romantic situation, would they be confident and cool? Or nervous and awkward?
Stuff like that.
There are no set traits to make a good character, this isn't some kind of RPG where you hope to build a character with perfect stats and powerful equipment. Everybody has flaws, and so would a good character.