Manipulating focus is a great way to force your viewers' eyes where you want them to go. D'uh, right?
Yet, I see so many glamour images that could have been greatly improved with a bit of focus manipulation when the photographer was shooting. I know, I know... it's a creative decision and those photographers chose not to use depth of focus as one of their creative tools for that shot.
Sorry, I don't buy that. I don't think all of those photographers much considered how they might exploit focus to enhance their images. I'm guessing many of them decided to shoot at small apertures because they were thinking more about keeping their models in sharp focus. Unfortunately, a lot of stuff in their backgrounds was kept in nearly as sharp focus. That's not necessarily a bad thing. Sometimes, it's the right thing to do. Other times, it keeps the photo in the realm of mediocrity.
For glamour photography, make that for the majority of people photography, sharp focus on the models or subjects is often important. (Unless you're going for a fuzzy, soft-focus, artsy look.) Usually, the sharpest focus should be on the model's eyes. (D'uh again.) We sure don't want blurry glimpses through those windows to the soul even if the models' souls aren't what many viewers of glamour images are gawking at.
Personally, it's rare for me to shoot a model above f/8 unless I'm purposely looking for more depth of focus... which isn't that often. I mostly prefer in and around f/5.6, plus or minus a stop, and, occasionally, wider than that. The more open the aperture, of course, the shallower the focus. The closer my framing, the more I generally prefer a shallower focus.
Just because your powerful strobes can deliver plenty of lighting power, allowing you to shoot at very stopped-down apertures, doesn't mean you should always be using that power. The most powerful monolight I own delivers a mere 500WS of power and I rarely have used that strobe at full capacity. In fact, the strobe itself gets used less than my 300WS strobes because I can't dial it down enough while keeping it in close to my models and still achieving very soft lighting. (Which most of my clients prefer when I'm shooting glamour and tease for them.)
Just some Hump Day tidbits for thought regarding the role of focus in glamour shooting.
The pretty girl at the top is Faye. I used two lights: A 300WS main light in front modified with a small, shoot-thru umbrella and a 300WS bare-bulb strobe from behind for highlights. For glass, I was using a Canon 85mm f/1.8 prime. Exposure was ISO 100, f/2.5 with a 200th of a second shutter. Mark Twain might have been talking about Faye when he said, "A face without freckles is like the sky without stars."