How do you tell someone what you look like in first person though? Or in third person close? Looking in a mirror is one way, but be careful with this. Consider what your character would actually do while looking in the mirror. He or she might examine their teeth to make sure no food is caught or there are no lipstick marks, but it is highly unlikely they will admire how straight their teeth are unless they just invested a bucket-load of money into that effort. Same with hair. A woman may go to great lengths to make sure her hair is just so, maybe examining closely to make sure dark roots are not showing. Guys might not be so intent on the mirror at all unless they are shaving, of course young people might be looking for pimples. All of these are clues into what your character looks like. Just remember, no one ever looks in the mirror and says, "My long silky black hair is so sexy."
There is another way, and I think it's about the best way I've come across so far.
Is that other person taller? Shorter? Fatter? Skinnier? Most of the time such comparisons are accompanied by an opinion based on our self-image, don't be afraid to make use of that, but don't overdo it either.
This comparison can be used for many things. In a fight, scoffing at how slow your adversary is, also tells your reader that you think you are faster. Maybe it'll pan out, and maybe it won't, but it's still a glimpse into self-image.
Okay now, lets make it interesting. All of the above is based on the average human description we are all familiar with, even such characters like werwolves and vampires are a familiar image and therefore we only need a few clues to hair color and general body build. Mostly, a few clues is enough; don't be afraid to let your reader build their own image of what your character looks like.
BUT, lets say you are not human. I am of the opinion that two arms, two legs, opposable thumbs, etc is the most efficient physical form; allowances made for our local lycanthrope members, since the two arms and two legs still apply, though they would be handicapped by not having opposable thumbs.
So keeping this basic form, lets say you are the perfect engine of war, and that you are constructed, not from blood, muscle and bone, but from energy made solid. Now the question is, how do you convey this information without blatantly telling your reader? I mean, you wouldn't walk up to someone on the street and say, "Hello, I am a human with awesome fighting ability. How are you?"
Being an engine of war, being a being of energy, it would be logical to put him in combat. You also need to consider the mind-set of such a being. This is not going to be a person who would admire himself, and if he were to look at someone who might qualify as a mate, she would have to be worthy, not pretty. An eye appeal would be secondary at best.
This person is not going to admire his killing hands for their deadliness, nor look in any kind of mirror to make sure his teeth are sharp. What he will do though, is ensure his weapons are the best they can be.
Now we need something to compare, something to concentrate on, something to fight. Being a creature of energy, age and/or power might result in increased size, since the limitations of bone growth would not be a factor. Also being a creature of energy, bone-breaking damage would only be an annoyance and a drain on energy, seen as blood, but not debilitating. Debilitation would come from the successful removal of a limb or armor. Both being part of the body energy, both could be replaced, but the body energy is finite unless replenished.
Now such mundane things as energy replenishment needs to be considered, and battle strategy might need to lead toward such a source if one is in the area, but battle strategy might also need to consider, "If I go to a point to shore up my energy, my enemy would have the same opportunity, and there is that chance that he might be able to keep me from it while taking advantage himself." Battles need to be carefully plotted. An engine of war, would leave very little to chance, unless he had no choice, and even the best can sometimes find themselves royally screwed.
But I digress - back to self-description. You have a character who is not likely to look down at himself and say, "Yep, I'm so deadly. My claws are sharp, and my armor is strong." This will be a silent assessment as he flips his claws together, absently worrying a flaw. He needs to keep an eye out for the enemy.
Okay, now lets make another assumption. All the people on this planet are of the same race. Under that assumption, they will have a lot of similarities. Take a look at your neighbor. He may have a different skin color or a different build, but he is still human, even some man on the other side of the world would still be classified as human, and human has a very basic definition.
Here comes the opponent. Herein plays the comparison. Is he bigger? Slower? Smarter? More arrogant? Is his armor harder? Are there weaknesses? Are his claws sharper, or have they been neglected? Are his back spines standing at alert or relaxed in arrogance? Are the sensory hairs on his head and down his back too thick to be very sensitive? Is there a weakness there? Is there a weakness anywhere, even on the bottom of his feet? Cut the tendons across the bottom of his feet and his speed is halved at least for a little while.
Can you see what I've done? By assessing the opponent, coupled with known weaknesses within self, I have told you a lot about how the main character looks. Add in action like running where toe-claws are vital for traction, or falls where some armor spikes might break, or the battle up front where damage is done and energy (blood) is shed, and your reader has a very clear view of what is going on, and no mirror in sight.
How do you describe self in your books? Any helpful hints out there?