Move, rotate, and scale the cylindrical projection gizmo using the normal move rotate and scale tools, until the checkerboard texture looks best.

Click the Cylindrical button again to deactivate it, and click the edit button. By default it will look something like this:

To conserve texture space, we'll be wantind to mirror the whole head. If you really need to do some asymetrical texture work for the head (like if the character had a big scar or something) then you may want to leave some areas un-mirrored. But for this, we're just going to mirror everything that can be.

So switch to vertex selection mode, select half the back of the head, Detach (Ctrl+D) Flip it horizontally, and move it over top of the other half of the head.

We also need to avoide any over-lapping areas. The ear has several parts that overlap others, so just grab the verticies and pull them outwards so that nothing is overlapping anything else.

Now do the same thing for the face. Select down the center, detach (Ctrl+d) flip it horizontally and move it over top.

When I mirror UVs, I usually select everything and do a Ctrl+W to weld the two halves together. You need to be careful when doing this in areas with lots of detail to the mesh (like the face).

If I selected the face and did a Ctrl+W it actually welds together some UVs that it shouldn't! This causes nasty distortions in the unwrap. So be careful to watch for problems like this!

All that was left after this was to adjust the top of the head so that it would deform as best as I could get it to. My intention is to do some polygonal hair with opacities, but when I do it that way, I still find it a good idea to have a hair texture on the scalp under the hair.

I also flipped the whole head because I'm just used to working on them in this way. So just fit the head into the square, render out the texture (Tools > Render UVW Template) set the size, click the button, save the file, close the edit window, and collapse the stack! Done! Fwew!