I'm looking for inputs for your preferences to where to place the horizon line when photographing a model. This is not about "rule of thirds" - this is about where on the model should the horizon cut behind the model.

What I was taught was never "decapitate" your model with the horizon line at the neck. Some also say, never have the horizon at the model's eye level for much the same reason.

Those guidelines leave a lot of places where the horizon can cross behind the model. Above the head, below the shoulders, waist, hips, knees, even lower. Camera angle and position can place the horizon in many position with regards to the model.

If you have a preference, please share, and if you know a creditable website of photographic instructors explaining their preference, please provide a link.

To illustrate:
1. The horizon line cuts through Olivia just below her shoulders in this image:


2. The horizon line cuts through Olivia at chest level in this image:
NSFW, 18+, Olivia in Red

3. The horizon line cuts behind Femina just below the hips in this image:
NSFW, 18+, Femina in Utah

Clearly, raising or lowering the camera angle could adjust the horizon line. There is a compromise with how that angle renders the model, but let's concentrate on just the horizon line for your opinions/critique. Examples welcomed.

I like number 2 the most. It seems to have the right balance of land and sky for the composition.

Cheers,
Noah

My suggestion is not so much about the placement of the horizon line but the composition in general.  Have you thought about opening the aperture wide open to make the background less distinguished when both you and the model are standing?  Other ways to "hide" the issue is for you to kneel or lay on the ground to put the horizon at the models feet or use a ladder to put it over the models head.

Your portfolio is quite diverse and good!  The one point I noticed is that you do not utilize depth of field much as part of the composition.  There are a couple where the aperture was opened to obscure the background but the model is usually quite close in those.  All of the long-shots with models have the background in focus.  For many of them it fits the composition but try play with the depth of field more and see what you get.