Alright, with a bit more time today hopefully this will be a bit more organized and coherent than the rant I put up last night on the absence of strong female leads. What I'm going to try to do here is talk a bit more about characters themselves, and how I've seen them relate in the worlds of Science Fiction and Fantasy. There will probably also be a bit more on yesterday's rant a bit more fleshed out.
Starting off though, lets look at the two rules about characters that hold true in pretty much any genre.
Rule #1: A character that is properly designed and fleshed out, when isolated, gender and ethnicity will cease to matter.
What this means, is essentially what it says, but in a more drawn out explanation is that a character that is actually a character. Fleshed out, designed well, have their life story and goals, they shouldn't be drawing on descriptive words from Gender or Ethnicity to describe them. Jobs maybe, but not those core descriptions. Not that Gender and Ethnicity aren't important, but if they are a defining trait of your character, you may want to take another look at the character.
Rule #2: You can ignore rule #1 provided that you know and understand it.
This comes down to artistic license and choice, when you know and understand a rule you can violate it because you are doing so in full knowledge of the rule's existence and reason for existence. This means the knowledge that comes from that understanding will still be present and protect you from the pitfalls someone who just doesn't understand would make when violating the rule.
For an example on these you don't need to look much further than the Sci-Fi movie Aliens and it's protagonist Ellen Ripley. Ellen Ripley is a strong character, a leader, made of stern stuff with some mothering overtones who really just wants to get along with her life. Even better, Ellen through the course of Aliens does the standard plot, namely she saves the day and gets the girl (Hicks). Separated from the story though, Ellen is still the same character as a male or female or any ethnicity. The fact that she is a white female is secondary to who her character is, and as such she is a 'real' character.
On the other side though, we have some common examples of the wrong way of doing this. Focusing still on women (and in the last case, via inclusion, other minorities) as these are what I see (again in Sci Fi and Fantasy) showing up the most often for the 'few' important female characters we do get.
Woman in Power
The Woman in Power is exactly that, a female character in power. However, by the very name of it a defining characteristic of this person is that they are female. This character is usually defined by over emotionality, a lack of logic in key areas, and in numerous cases hypocrisy. This is generally - in my experience - a female character, and while there are male characters who shouldn't be in power they are often not quite as bad, or infuriating, as a Woman in Power. One of the better, and recent examples of this is President Roslyn of the new Battlestar Galactica series. She regularly gets caught up int he emotion of the moment, regularly gets in the way of the 'sane' decision, and on numerous occasions through out the show is out right hypocritical.
I am psychobitch!
This one is a bit weirder, especially because there are so many examples of it being done well that I hate to list it as a bad thing. However, it is also done wrong a lot of times to. For the example I'm going to give here I'm going to use what I feel is one of the better examples of the trope. Let's do it by comparing two hot shot fly by the seat of their pants pilots. Maverick from Top Gun, and Star Buck from the new Battle Star Galactica. Both of these pilots fly like they have nothing to lose, edge of their seats, absolutely crazy. For Maverick the reasoning? Daddy may have done it wrong, and he wants to prove that the family did it right by being the very best. Star Buck however "needs" (again StarBuck is a solid character, this is just the easiest example to draw from) a much more convoluted story of child abuse and trauma. This same comparison is a regular occurence however for women when taking more militaristic roles in their story. Their seems to always need to be a reason above and beyond 'something to prove' or 'just fell into it', and usually this reason is a long tale of betrayal and abuse that has them one step from falling over the edge.
Finally, there is just the 'Stereotype' in general. While sometimes stereotypes can be good, when it comes to stereotypical characters they're usually bad. As said in Rule #1, gender and ethnicity should NOT be defining characteristics for a character, especially one that you want people to respect.
So where does this leave us? Well, when you're trying to make a character (or analyze one) look at these things. (Need to try for something productive here)
Motivation: What is the character after? What gets them up every morning? Why do they keep slogging through the world and life? What picks them up when they take a beating? Knowing someone's motivation is a big step in understanding the character. Even if it is something as simple as "live another day" or the character is looking for their motivation.
Background: Where the character has been, and what they've done, as much as motivation this has the most impact on who a character is. You really want to treat this like building a world, everything should make sense inside the story. You also want to expand on what you put in things to their logical conclusion. If you're doing something truly nuts for the character, maybe look it up, you don't need to go super in depth but a bit of research will help a ton with making the character feel real.
Personality: Finally we have personality, and you do want to do this one last. Motivation and Background will play a major part in this, but sometimes people defy both of these things in how they come out to be. However, when you have a feel for the personality, especially with the background and motivation.
and...that's about it.