How do you handle downhill sharp turns on trails? My current technique is to go straight into the turn, let go of the handlebar, spin my upper body, and hope that it comes out okay. Mostly this works, but it’s not very graceful. And on steeper downhills it doesn’t feel very secure…
Generally I’m on dirt trails like the one below, not too rocky, but occasionally with roots and some rocks.
thanks in advance
I’d say there are two kinds, turns you can ride as a turn, and turns you have to “pivot” in.
By riding “as a turn” I mean that you ride a relatively smooth curve, pedaling the whole time, no stopping and twisting. The corner in the image looks rideable like that to me, but on some steeper and tighter corners this becomes almost impossible to do. However a few pointers to maximize your chances:
By “pivoting” I mean coming to a stop (or almost a stop) and rotating your tire on the ground. I would leave my hands on the handle. The pivot is easiest with horizontal cranks and if you generate a bit of a hop to unload the tire, so it doesn’t resist the turn. (You can practice this on flat ground while hopping). Your tire doesn’t actually need to leave the ground, but a bit of a bounce really helps.
In addition to Finn’s suggestions, I’ve always found it helpful to gently push my knee slightly in the direction of the turn when cornering through tight bends without stopping. At first, you can simply become aware of this or practice it. For example, you can find a drain cover or something similar to ride around in a tight turn. Then, when you can do that well, it also feels much more natural on the trail.
As Finn already mentioned, you can of course turn on the spot or even hop once or twice when the trail corners are too tight. In my opinion, however, stopping or hopping disrupts the flow of riding and should only be done if really necessary.
I tend to ride the brake into turns like that, pedaling into the brake, managing speed that way. Also use the handlebar as needed to guide uni around,also powering pedal strokes at right time. Sometimes it’s a beautiful thing, other times… not so much 
As part of that, on the flat I often practice progressively tighter figure eight turns, pedaling into the brake, so on trail with tight, irregular descending turns you’re mainly managing just managing speed out of the corner and falling back on what you’ve practiced.
I feel like this discussion will be very relevant for the upcoming XC at UNICON22. There is one section of a zigzag in a slight downhill with a lot of very tight turns.
I’d add that one of the limitations is grip. When you ride “as a turn” you ride more on the edge of the tire, reducing grip. So in the same turn, in a day where the terrain is too dry or muddy you may have to “pivot” while on a different day you may be able to ride “as a turn” because the terrain has more grip.
