To find the proper position, make a circle with the arms and the 帛紗, then move to the L so that the 帛紗's R side is over your L knee. Make sure the 帛紗 stays horizontally parallel to the floor (Miya 25)
Hiromi said how you can practise this a lifetime to manage to really put your heart into it. Also, breathe out when bending it; as if you're compressing the air in the room.
Christoph (24) had a good take: it's a slow motion version of pulling the 帛紗 apart to get the dust out.
KM also suggested to practise this with the “energy circle”.
for handling 唐物茶入 as in 盆点（ぼんだて） is 真. This is where you form 81 (or 88?) layers. At Ulrich's seminar in July 2017, he mentioned the number of layers, and that this represents how they contain the universe.
When you 真捌き, keep the 帛紗 standing until the very end, gripping the little packet with a R overhand grip to move to clean the 茶入.
茶入: When pulling down the 帛紗, form a circle with your R hand.
棗: Don't use the 帛紗 like a brush, keep it perpendicular to the ground.
茶杓: Make sure there's enough air when cleaning!
Generally: Don't use your L thumb to fix 帛紗 on your palm!
茶筅
Also called 茶筅調べ（ちゃせん しらべ）, inspection of the 茶筅
Ulrich said in June 2017 that the 茶筅 should be raised by x, where x is half the distance from the ground to the level of the tip of the 柄杓
From above if on lacquered surface, not for 平茶碗!
Modern teachers don't like the トック even for 子習, since it bears the danger of breaking the 茶碗, and it's a bit pretentious.
After the の字, make sure you lift both hands with the lower back, without one of them moving independently.
When pouring cold water into the 釜（かま） or left-over hot water, make sure not to handle the 柄杓 like an oil seller. That is:
don't shake off the last drop of water
don't lift the 柄杓 while pouring. This is called 油柄杓（あぶら ひしゃく）, which means oil ladle, and already was a pet peeve of 利休!
When drawing cold water, because I have big hands, no need to draw back; and make sure thumb doesn't go over 柄杓.
In 炉, the index finger is about 1 cm away from the node. Because of this, pick it up where it makes sense, either on the 炉縁 or on the 畳 ribbon (Miya 25).
A good way to remember whether to do かまえ or not: If you move something afterwards while holding the 柄杓, you かまえ. So in 長板濃茶, you do it!
Room
open the ふすま: first movement when opening and last movement when closing needn't be the flat-stretched hand, can also be the thumb, akin to when you close the 鶴瓶 lid.
Sitting down:
Keep your feet tucked together and heels pressed against each other. Don't slide back with the L foot! (I used to do that to save my knee, but it's no longer necessary.)
When moving your upper body back after putting your feet down flat on the ground, push through your lower back.
Walking
When turning, slide your big toe of the moving foot against the inside of the standing foot. Like this the 着物 doesn't open, and it looks very tidy.