I use tea tree oil anywhere from three to five times a week before I got to bed. Like another poster, my hair is too short to put in a ponytail, so what happens is that all of my hair ends up getting the oil, which does not appear to be a bad thing. 
I do exactly as Chaz demonstrates on QVC: one full dropper in the front left, one full dropper in the front right, one full dropper in the back left, and one full dropper in the back right. I spell that out because many times he says "one full dropper in the front and back" showing four different places. That always threw me because I thought that meant one full dropper is dispersed/spread out in four places; but then one time he said "four full droppers total."
I don't mind the smell because I'm used to using Australian Tea Tree oil and spray for when I travel to jungle areas where there are lots of mosquitoes at night. Tea tree works wonders at keeping those pesky things away from me.
I learned early on to put the oil on a couple of hours before I go to bed. One time I didn't and my head was quite saturated. I put a towel on my pillow to protect it, but feel that much of the oil ended up being soaked into the towel instead of my scalp that night!
Someone indicated that the oil should not be massaged into the scalp. I'm not sure why that shouldn't be done. I massage it into my scalp for about five minutes. I have thin/fine hair, and was starting to have loss of hair, which was beginning to look really bad. One of the remedies I read about online and heard on talk shows was to massage the scalp for five minutes every evening to stimulate growth. So I started doing that six months ago. I also started using WEN tea tree cleanser and oil in June of this year, and also increased my biotin intake. I'm happy to say that my hair is not thinning like it was and seems to be filling in nicely. Not sure if it is the scalp massage, the WEN, or the extra biotin; however, I continue to do all three because I think they each in their own way contribute to me having healthier hair now.