"like 12 feet tall." 7-8 foot is about the standard for Northern Calif. They can get over it if they really want, but its rare enough to call it ok. Zoning foks go nuts if you go much higher.

I was told once they hate the smell of human hair.

I have little cheescloth bundles with my cut hair hanging around my garden. In the last 3 years I have not had any intruders. They frequently pass by within 40-50 feet but don't visit the garden

I can't neccessarily attribute that to the hair but so far so good (*knock on wood*)

Another tactic frinds of mine use is to send their meat-eating members of their houshold to mark their turf.
This is also supposed to help keep coyotee away from their animals.

someone recommended to me about using Irish spring soap, i think the fresh river scent or something like that. And i didn't notice any deer visitings in the garden the soap did have various racoon clawmarks on it.

Okay. I mentioned an egg mixed with a gallon of water a couple years ago.. Since then I have been using it, and It really works! (and smells bad, but only initially) Mix in a tablespoon of soap for longer lasting protection. If it rains alot or you get the plants wet on a regular basis you need to reapply. It doesn't have to cover everything, just be nearby so they can smell it. I have a small herd literally living in my yard and this keeps them away from my flowers and ornamentals. I do have a fenced area for my main veggie garden. Also they don't like walking thru pumpkins and squash so it you plant these and they get big enuf, then you can plan other stuff amongst them.