I think i've finally done it, this is the 4th yarn tail I've made, and so far have had nothing wrong with it like the last 3. I've pretty much worn it for a week straight (tucked under my pants when outside my room, and one accidental forgetting to tuck it in before walking through the house, which got my mothers attention and she chased me through the house thinking i killed a dog and cut its tail off LOL) and this one, unlike the other 3, fluffs right back up with just a quick brushing and remains thick. Had problems with the previous ones where i spread the yarn too far apart so they were very thin and looked mangy just a few minutes after brushing.

(see my gallery for the previous attempts and how i made it)