The answer is simple, I don't!
In all my talk of scale and proportion you'll never find me saying everyone should model their avatar after their real world self. My own avatar is hardly "realistic", and a couple of people have pointed that out, as if suggesting I'm hypocritical in my talk of proportions.
Let me put it this way. Recently someone said to me that most people find normal human proportions"ugly" and that they'd rather look like a J. Scott Campbell illustration.
I emphatically agree!
The thing is, Mr. Campbell understands human proportion and uses that understanding to craft attractive figures.
Below, I've taken a Campbell figure and overlayed the same proportion guides I use in Second Life when discussing proportions.
|To look like this in SL, as much as to draw a figure like this,|
requires an understanding of realistic proportions.
As you can see, the lady here is just over 8 heads tall. Probably about 8 and a quarter. So she has a much larger head than the average SL avatar.
She also has a wingspan comparable to her height. It's actually slightly longer to emphasize the tall figure and compliment the longer legs, which are only slightly longer than half her height as I suggest for those intending a "long legged look" in SL. Longer arms are part and parcel with longer legs.
None of this is by accident. It all comes from a basic understanding of human proportion and how to manipulate it to achieve a desired appearance.