Making a tail thicker?

Does anyone have any tips to thicken tails? My paint's tail is moderatly thick at the top, but as it nears his hocks it thins quite a bit. I'm guessing it's just breakage, but the look of it is driving me nuts. Haha I've tried tying it up in a tail bag, and it grew rather quickly that way, but stayed thin.

The best tip I can give you is to NOT do anything with it at all. Do not brush or comb it on a daily basis, this only causes daily breakage. The less you do with it, the better.

If you must have that "freshly groomed" looking tail, I would spray it with a very good detangler (I like Mane and Tail because he actually conditions instead of drying) and "finger" comb gently. Don't put any products on it that contain silicone or alcohol (show sheen, etc), as the dryer the tail is, the easier it is to damage.

I keep Cin's wrapped up (braided and then rolled up and vet wrapped) to help protect it, but only in the winter when there aren't any flies. You must keep watch that your horse isn't irritated by it enough to rub. I keep Cin's up for about a month, and then finger comb, and rewrap.

Stay away from anything that may dry it out, including washing it too much. Condition condition condition. If you use a product that goes on the skin such as MTG, test first to make sure your horse isn't allergic to it.

Good hair, hooves, etc. all come from good nutrition.

Cinny- His tail is brushed once a week tops, but it's been in a tail bag for the past two months.

Mudpie- He is in good condition except for the tail. Like I said, it's mostly just breakage, the hair itself is healthy near the root, but only stays thick about halfway down, then it gets thin.