Well from what I can see the UV map is very neat, maybe could use more of the space available, but it looks like a good layout.
You shouldn't completely stop using photographs, because the professionals sure as hell use them! - It takes a lot of practice to draw textures well, but if you get into the habit of always using a photo reference, you can cut the usefull bits out and use bits as guides and base textures. For example, if you had a wrinkly cloth texture, using that as a kinda base for your clothing is a good idea. Work in layers, I tend to have the reference stuff as a background, then detail bits go on top, shading and lighting, colour adjustments etc.
It's really best not to start from complete scratch, rely on textures to give your work an organic natural feel. For heads, well using a distorted face might be a good start, like stretch out a face, trying to get the eyes and mouth in the right place, then use the skin tones to draw the rest of the face and hair.
Practice is the most important thing, it takes a long time to get really good textures, but once you have a technique down, well things get a lot prettier and a lot easier to produce.
