One useful tip on collecting a hair sample:

If you don't like the idea of chopping out a big chunk of hair from a specific area, you can use a pair of thinning/blending shears, which will remove hair in a more diffuse manner from a larger area, thereby avoiding the "missing chunk" look. You'll not even notice anything looking odd, and can still get a good sized sample.

~FB
... who still doesn't like the idea of giving up ANY of what's left of his own