I collect mine in the sink, then flush them down the toilet. I heard when I was a child ppl can collect your hair and do voodoo or witchcraft, so I always flush my shed hair and anytime I sweep up hair on the floor...it either goes down the toilet or in the fireplace during winter to burn.
When I'm adding product to my hair and I get shed hairs on my hands, I keep an old hair towel on hand to wipe my hands and the hairs on. I'll either shake the towel in the toilet when done or into the sink, collect the hairs, then flush. I collect any hair balls in the shower drain with a drain catch (snags hair with teeth like a Tangle Teezer).
My neighbor is from Afganistan, and she said in her country, the women take their shed hair and plant it/bury it under a beautiful, strong tree or large bush. They say the tree as it flourishes will make your hair grow also.
Some ppl also just throw it outside, as the birds use it in their nests. I find the tradition from my neighbor's country to be very interesting, and she insists I do it b/c the women have long, beautiful hair there that do.