Setting up UV's for texturing

Hi there… sorry for the noob question here… but…

In my case, I’m working with full human figure. For now though I’ll just focus on the head.
I’m going in and UVing and texturing my model. From what i understand it’s a good thing to keep my texture map as small as is reasonable. So I’d like things like the left and right side of a head to overlap in the UV editor so that all I need to do, is create a half face texture… right?
What I’ve been doing is:
Creating seams, unwrapping, selecting half of the head and moveing it over top of the other half, and then going vertex to vertex and snapping them together so they share the same UV space. Kinda tedeous… so I thought… maybe I’m doing this wrong?
Which brings me here.
Am I doing this wrong? Is there a better work flow? Something a bit more stream lined? Or do I just grin and bear it?

The mirror modifier also mirror the UVs so if my charater is completely mirrored, I abuse it to save me time.

Regarding your texture spaces you’ll also want to keep things in power of 2 increments. So the pixels length or width should be 2,4,8,16,32,64,128,256,512,1024,…

Some stats (final fantasy character in 8,9 used texture sheets that were 128x128 images) final fantasy X used 256x256. Newish games use 1024x1024 per character up to 2048x … The texture sheets do not need to be the same width by length so you can mix and match. 1024x512 and so on.