I'm the opposite of everyone :]
I don't brush the tail ever unless it has been washed and conditioned.
I don't keep it braided because if they catch it on anything it will rip out big chunks instead of a few strands.
I don't use any sprays etc. that contain silicone.
I wash the tail when I wash my horse. Shampoo, condition, brush out.
I either leave it out natural or I use a tail bag that attaches to my rugs so I don't have to braid it, and if the tail bag gets caught it just un-velcros from the rug, it doesn't pull the tail.