The photo study really was just a photo study: I copied a photo and tried to get it as close to what the photo looked like as possible. It's a lot easier to copy a photo than it is to draw anything from imagination (even with reference), so it came out a lot better than what I can normally do. Other than that, it wasn't any different from how I draw anything else.
The speedpaint did not use any reference at all. I just started drawing and didn't stop for an hour. The one I've been working on in the streams, I use some reference, but only when I get stuck really. She's one of my boyfriend's characters, and she was created to basically introduce this concept in his setting. She's a type of genetically modified human built for combat, and their most notable features are their bull-like parts. I wanted to make a proof of concept piece for him for Christmas, so I didn't want to spoil the surprise by talking to him, so all I had to go on was her name (Xia Sengupta) and her intro on the type of genetically modified human she was. The name suggested that she was probably a Chinese/Indian mix, so I was going for that, and then mixing in some various bull-like features into the face (the square nose and jaw being the big ones outside the obvious).
Hope that made sense, I'm somewhat half asleep right now.