it really depends on what you are doing and what the ground conditions are like. I think tails look very smart when they are taped up for XC or hunting.
But any other time, I like my horses tail to be neatly pulled, but not to the extreme, and reasonably long.
I would love to put Ron's tail up for hunting, but it only ever lasts 2 minutes (cos he likes to scratch his dock in the trailer!) plus I have this sneaking suspicion it would make him buck!
as it is, his tail is a hand-span below his hocks and 'banged'. I don't pull tails cos he's out in the field a lot during the winter and i don't like the look so it's left natural at the top.
I wash his tail as little as possible, but when i do it then soak (yes soak) it in about 500ml of Alva Dazzle tail conditioner - helps repel the mud, sweat, and knots for ages, then a quick rinse of the bottom third after hunting is all it needs to look clean again.
If you want to look as smart as possible then definitely plait and then sew it up. No tape, tape looks very scruffy. Our hunt horses have their tails pulled then the remainder to the end of the dock plaited then the bottom sewn up. They llok very smart.
Tails up from opening meet through to March-ish time when we usually revert to not plaiting for the last few meets. Personally I tape up a well-pulled tail and make a neat job of it which I don't think has ever come down, but I can sew them up if required. I have seen plenty of badly put up tails, usually taped, which don't last longer than the meet!
Just had a look at your tail k9h and it is extremely smart. I have done them like that but mine are now pulled to two-thirds down the dock so can only be plaited from there.
I remember doing four like that after a rather boozy Xmas day lunch ready for Boxing day and spending the whole night petrifed that I'd find all their tails had dropped off by morning! (though, unlike tape, there isn't actually any circumferential pressure anywhere on a stitched-up tail so this is highly unlikely!).