I've just stumble across an easy way to texture a 3d head model. So all these times I've been: adding Unwrap UV modifier, flatten mapping, and take a long time trying to arrange the pieces of flattened maps into a face map, which was a really tedious and boring job...
So I was following this character modelling tutorial called Joan of Arc, and it taught me some great technique on modelling and texturing a character that I thought I'd take a note here.
Easy face texturing
1. Click on the face and apply a "UVW Map" modifier, then choose Cylindrical Mapping.
2. Click the "+" sign beside the modifier and select "Gizmo".
3. Use the move, rotate and scale tool to position, turn and resize the gizmo so that it covers the entire head model in a tidy manner.
4. Next, right click on the UVW Map modifier and select "Collapse All", and the modifier will be collapsed into the model, leaving only the Editable Poly/Mesh modifier on the stack.
5. Then, add a "Unwrap UVW" Modifier, and click on the "edit" button, there'll be a nice looking UVW map waiting to be modify on the screen.
6. Though it looks pretty good already, it's still not very satisfying here. I'll make some modification here. Select everything an rotate them so that the face is in an upright position.
7. Look up and closer and there'll be some thin-looking map over there. Those are the unsatisfying stuff I'm talking about.
8. Select them all at once, and flatten mapping it.
9. I'll leave them for a while now, will get back to them later, so just place them at the top for a while. So now, the face look a bit to the left, and I wanna arrange it so that it'll be in the middle. I first select the other half on the right, detach it (right click > Detach Edge Verts) and place it to the left, and weld all the vertex there (right click > Weld Selected).
10. And the face looks much more settled now.
11. Took some more time to further modify it and I got this.
12. What about the unsatisfying map from earlier? Here they are, arranged together with the face without crossing over each other. It wouldn't take too long to make this part... for those who aren't still beginner.
13. So I've got my face mapping done and it's about time to texture it in Photoshop.
Click on Tools > Render UVW Template... When the box appear, choose the size (mine favorite: 1024x1024) and click the Render UVW Template button. A rendered UVW template will shows up. Click save to save it...