you know what I do... I look at pictures of people, sometimes random images, and I give them character and personality and see where my mind takes me in creating characters.
It's weird to think each face might mean something different and the thoughts that enter our minds as writers may be as far from the truth as ever, but it inspires me anyways. Thanks for posting that. I've sometimes been stuck with stories, not sure who my characters even re and I've found that putting a real face to them (or body, or clothes, or even a silhouette in a window) gives me a clearer creative perspective and I sometimes fly past my block and the writing just comes more naturally. Maybe I'm unusual in that respect, but it works for me.
Nice photo collection you've found. Personally I think the most useful guides for drawing faces (as with other body parts) are those that break down their proportions and anatomy (e.g. skull features and musculature), but simple photos are still fine references.
I must admit that right I have some trouble making different characters' faces look distinct, or what some call "same-face syndrome". It's not so hard if the characters come from different racial or ethnic groups, but when it comes to characters within the same race or ethnicity, the same-face really sets in. For example, I could draw Ethiopian characters who all have different facial features from Nigerian characters, but no so much making the Ethiopians look individually different (that is, without fiddling with their hairstyles, clothing, or skin tones). I am not sure why that is, although maybe modeling certain characters' faces after specific individuals might address the problem.
In addition, I've gotten criticism that my female characters in particular all have the same body type, namely the classic hourglass figure. I'm more ambivalent about this complaint because it so often comes from women with a "fat acceptance" agenda that I consider problematic. Obviously women will naturally vary in certain properties like height or stockiness, both within a certain ethnicity and throughout the world, but a lot of what these activists call "body diversity" is symptomatic of modern civilization's high-calorie diets and ensuing obesity which really isn't healthy. Mind you, I'm open to drawing overweight or underweight characters if the situation ever called for it, but they'll never be my preferred type of woman to draw.
And besides, since I draw so many African female characters, I really don't want to propagate the old "fat ugly black woman" stereotype.
I used to draw portraits and people a lot in my late teens and early 20s. I started with an anime style as that was my inspiration, then moved on to more realistic proportions and shading - I found the work of Boris Valejo inspiring in how he did his shading and colours of skin, he used all sorts of skin tone that reflected the environment and theme of the picture. I also drew on inspiration from the French painters like David and Ingres.
In terms of drawing people you can't beat the real thing if you can arrange this - I used to draw my friends for portraits or go to life drawing classes for figure - preferably this should be in the day time with natural lighting. You can get in close and see much more in real life than looking at pictures.
When I'd draw figure I'd start on proportions and posture/pose first - drawing the main lines of the spine, shoulders/hips and then the limb proportions, and then start building up the mass of the body. I'd work on details last such as clothing, musculature, hair etc. Then I'd go into particular detail for the things we look at a lot, or what I wanted to emphasise - the eyes are a big one.
For the face I'd do the same, drawing the basic face shape, then putting in the eye/nose/lip locations/size etc. Only when this was all in would I start detailing, rubbing out the underlying sketch lines as I went. I used pencils if I cared about the end result, as I could always rub out, whereas if I just wanted to doodle I used pens.
I started with an anime style too, but I've gradually moved toward a more realistic approach that still retains some stylized elements. I call it Westernized/quasi-manga. It's a nice style to work in because I can play fast and loose with proportions, exaggerating features for a distinctive look, while still keeping that realistic tone. And I get to play up the eyes. I love doing eyes. They're the most expressive part of the face, and the part that a lot of people overlook when they're drawing facial expressions. If the eyes aren't involved, the expression looks so stiff.
So you draw from photo references? The whole reason I started using the Humanae Project was because I wanted to work through my absolute hatred for working from photos. Most of my faces and figures are drawn completely off the top of my head. I've been forcing myself to work from photo references just so I can say I'm able to. It has not been an enjoyable endeavor. XD
I didn't use to draw from photos, similar to you I didn't like them and I used to draw a lot from imagination instead. Having said that having all those faces in the tumblr link is fantastic and it does give inspiration for all sheer diversity of people - as you said, its beautiful to see. And it also spawns ideas for characters just like Caged Maiden said. I find that with the story I'm currently writing I'm often considering how the characters look - even if its a type to suggest character and how they would exist physically in my world, it gives me a sense of grounding rather than them being words on a page.